Five-year-old Elsie Ryan has not yet asked why her mum died or what happened to her afterwards.
But when she does, her dad will tell her that her mother Campbel Giles was part of something special.
The 41-year-old political adviser and former journalist died on February 2015 after metastatic breast cancer spread to her liver, bones and then her brain.
She left a gift for researchers.
Before she died she pledged to be a part of a study where cancer patients donate samples of their tumours after they die, in they hope they will yield clues leading to new or improved treatments.
"Some people sell beanies or socks and I suppose this is her little contribution," said Campbel's husband Matt Ryan.
"It was also a bit of comfort for me, that even though she was dead, she was going off to do her last significant act."
The Cancer Tissue Collection After Death (CASCADE) program has been running at the Peter MacCallum Cancer Centre since 2013. It has so far involved about 50 people with terminal melanoma or breast, ovarian, prostate or lung cancers.
These patients give permission to undergo an autopsy and tissue collection within 24 hours after they die.
It is important because access to the tissue of patients with widespread cancer is limited as they do not often undergo surgery.
Associate Professor Sarah-Jane Dawson, from the Peter MacCallum Cancer Centre, said a key problem with treating cancers is that the same cancers can behave very differently from person to person.
"To take the example of breast cancer, usually no two women who are diagnosed with breast cancer have the same disease. And that's really the same for all cancer types," Professor Dawson said.
"There is a lot of individual variation that exist between patients, even though they've been diagnosed with essentially what's called the same disease.
"It's is very important for us to get a handle on the individual characteristics of someone's disease if we are going to treat it most effectively."
It is also hoped research may help explain why secondary or metastatic cancers are more difficult to treat.
When Campbel Giles was first diagnosed with cancer in June 2012 - when Elsie was just a toddler - it was already at an advanced stage.
She had gone to doctors before she found out she was pregnant, with a lump in her breast, but it was not diagnosed until after she kept going to the emergency department with pain.
During her career, Campbel worked for Border Watch newspaper in Mount Gambier, Shepparton News and was bureau chief of WIN Television in Shepparton.
She would later become a political adviser for the state Labor governments under premiers Steve Bracks and John Brumby, and for federal Labor MP Brendan O'Connor.
"If I was looking for an adviser who held her tongue and kept her opinions to herself I made an awfully bad choice," said Mr O'Connor in a speech to parliament days after Campbel's death.
Matt fondly describes his late wife as loud and opinionated, but also very kind.
While living in Darwin, he recalls her running around picking up itinerant Aboriginal people (locally called "long-grassers") and taking them to a shelter as a cyclone loomed. She almost didn't get home herself, he said.
He said Campbel was asked to participate in the CASCADE program the same day she was told that the cancer had moved to her brain and "there was nothing left in the toolbox".
"The lady from CASCADE come up and spoke to us within minutes of that news and told us to think about it. Campbel said 'I don't need to think about it, I'll sign up for it'," he said.
"I suppose it's a legacy thing. I think it was always her hope that it would be her tumour that would be the key to unlocking a lifesaving treatment."
The CASCADE program is ongoing and tissue samples are being used by researchers involved in the Tumour Heterogeneity Program, funded by a $2 million grant by the Australian Cancer Research Foundation.
Another aim of the program is to develop a potentially lifesaving liquid biopsy that will detect more types of cancer than current tests.