News in 5: Family's plea to missing woman; The benchmark for marriage equality; New ovarian cancer app.

1. “Give me a sign you’re okay.” Family’s plea to missing Victorian woman.

The family of a Melbourne woman missing for four days has made an emotional plea for her to contact them or come home.

Kayla Steffen, 24, was last seen by her housemates at their Altona North home early on Friday morning and police are concerned for her welfare because she has a medical condition.

The woman's sister Phoebe Steffen says her sibling, an amateur artist, seemed "a bit distressed" before disappearing and begged her sibling to make contact with the family, AAP reports.

"If, for whatever reason, you don't want to come home, please just give me some sort of sign or something that you're okay," she said.

The missing woman's mother, Jo Deppeler, described her as funny, beautiful and caring.

"Our daughter's gone missing and I don't know where she is. There's no words to describe how that feels," she said.

Anyone with information is encouraged to contact CrimeStoppers on 1800 333 000.

2. Marriage equality will be granted if 50 per cent vote 'yes', Prime Minister confirms.

Australia kicks off postal survey on same-sex marriage https://t.co/9Y2kHlBgcB

— BBC News (World) (@BBCWorld) September 12, 2017

Prime Minister Malcolm Turnbull says the government will facilitate a private members' bill to legalise same-sex marriage if the yes vote garners more than 50 per cent.

"That's democracy. A majority is a majority whether it's a big majority or a little one," Mr Turnbull told KIIS FM Radio, AAP reports.

Mr Turnbull said neither voter turnout nor how narrow the margin was would affect the government's position.

"I'd be delighted to see a yes vote and I'd be especially pleased to see a high participation," he said.

The Australian Bureau of Statistics is aiming to get the survey forms out to 16 million voters by September 25, with the first forms in mailboxes this week.

3. New app designed to help women living with ovarian cancer.

Sept is Gynaecological Cancer Awareness month! Here is a myth buster visual to ensure you know fact from fiction ... https://t.co/D29qfXdX6E pic.twitter.com/deqCmLzTn2

— QCGCResearch (@QCGC_Research) September 4, 2017

A new app is giving women with ovarian cancer some control back by allowing them to monitor in real time their tumour markers.

Tumour markers are specific substances, usually proteins found in blood, urine, or body tissues that are produced by the body in response to cancer growth. Elevated levels often indicate a recurrence of cancer.

Gynaecological oncologist Professor Andreas Obermair has no doubt the smartphone app, launched by Australian charity Cherish Women's Cancer Foundation, will improve the lives of the 1500 Australian women diagnosed with the deadly disease each year.

"The message that I get is that patients feel a sense of control, a sense of self empowerment and also reassurance because markers do trend up and down," he said.

"If the marker is 13 and it was 10 the last time then the patient gets upset, but having the ability to scroll back to see that it was 16 maybe three months before provides reassurance. They can actually see that this slight up and down is perfectly normal," said Prof Obermair.

It's also hoped the new app will assist in earlier detection of cancer re-occurrence. "Sometimes when we detect a re-occurrence early we can treat it much better," said Prof Obermair.

You can view and download the app here. 

4. Apple unveils new iPhone, a cellular watch and a 4G television.

Apple unveiled the heavily-anticipated iPhone X #AppleEvent https://t.co/WyP4MO10Jh pic.twitter.com/GMIG2mim8A

— FOX Business (@FoxBusiness) September 12, 2017

Apple has rolled out a new version of the Apple Watch, a new iPhone and a 4G television at the company's biggest product launch in years.

Chief Executive Tim Cook called the iPhone X (pronounced 10, not 'X') "the biggest leap forward" in innovation since the first iPhone was released 10 years ago.

The iPhone X loses the home button; offers an edge-to-edge screen; and will use facial recognition to unlock the phone. Apple also unveiled a new iPhone 8 and a larger 8 Plus with upgrades to cameras, displays and speakers.

Those phones, Apple said, will shoot pictures with better colours and less distortion, particularly in low-light settings. The display will adapt to ambient lighting, similar to a feature in some iPad Pro models. And both iPhone 8 versions will allow wireless charging.

An Apple Watch was also released, including built-in cellular. And the tech giant announced Apple TV 4K, which will stream Ultra HD movies from major Hollywood studios purchased through iTunes.

5. Donald Trump becomes grandfather for ninth time as son Eric welcomes a baby boy.

.@LaraLeaTrump & I are excited to announce that we are adding a boy to #TeamTrump in September. It's been an amazing year. We are blessed! pic.twitter.com/ENrhdxdziA

— Eric Trump (@EricTrump) March 20, 2017

US President Donald Trump's ninth grandchild has been born, son Eric Trump has announced.

Eric and his wife, Lara, were "excited to announce the birth of our son, Eric 'Luke' Trump," he wrote on Twitter on Tuesday.

The baby is the couple's first child. And the president already had eight grandchildren from his oldest children, Don Jr and Ivanka.

To read more of this story, click here.

6. New program to help Australian high school students get into STEM.

The Amgen Foundation, in partnership with The University of Sydney, today announced the launch of the Amgen Biotech Experience (ABE) in Australia as part of a $10.5 million investment in science education.

The three-week in-class initiative provides intensive professional development for teachers as well as teaching materials and research-grade equipment to classrooms to help educate students about the concepts and techniques scientists use to discover and develop medicines.

International research indicates that 75 per cent of the fastest growing occupations now require skills and knowledge in STEM - Science, Technology, Engineering and Mathematics. However, Australian student results in mathematics and science have failed to keep pace, stagnating over the past 20 years.

The project will engage an expected 5000 students and 60 teachers in New South Wales over the next three years.

"Through the ABE, students will gain an understanding of medical applications of biotechnology, with a focus on insulin," Dr Hannah Nicholas, who is a Senior Lecturer in Molecular Biology and the University of Sydney’s ABE Site Director, said in a press release.

“The Amgen Biotech Experience has already been well received by schools around NSW participating in the pilot and it’s been amazing to see the students learning so much from this experience.”