Collins said his goal of helping Mandi and others like her "gets me out of bed. Honestly, this is very, very important to me. It's more important than anything I've ever done.
"She's just like my daughter. It's really that simple," the immunologist says. "I don't know, God is really an amazing God. I'm certain that he put her here for a reason, and I have to think my daughter died for a reason to get through the day. So, maybe this is it."
Mandi says, "It's now just a waiting game and hoping someone will sign up that will be a match. ... I don't worry into the future. I just hope everything will fall into place."
For more information on how you might be able to help Mandi and others like her -- either by donating umbilical cord blood or bone marrow -- click on becomemandishero.org or natashasplace.org. Additional ways to reach out and help can be found on Mandi's Facebook page.