People.com Celebrity Parents 'The Challenge' Star Ashley Cain's Baby Daughter Undergoes Stem Cell Transplant After Leukemia Returns Ashley Cain said his 5-month-old child is now on "the toughest journey imaginable to save her precious life" By Gabrielle Chung Published on January 18, 2021 08:33 PM Share Tweet Pin Email Ashley Cain and daughter Azaylia. Photo: Ashley Cain/instagram The Challenge's Ashley Cain is opening up about his infant daughter's health three months after he first revealed that she had been diagnosed with leukemia. In an Instagram post on Monday, the reality star, 30, revealed that his 5-month-old child, Azaylia Diamond, has started a stem cell transplantation procedure. "Today was by far the biggest day of our lives. One that we have been hoping, wishing and praying for. The day Azaylia received her stem cell transplant and begins the toughest journey imaginable to save her precious life!" he wrote alongside a slideshow of the newborn in the hospital. "We believe in you princess," Cain continued. "You are strong, you are mighty, you are courageous and God is with you! 🙏🏾 You got this Likkle Lion. We love you! ❤️ LETS GO CHAMP! 💫." The Challenge's Ashley Cain Reveals 2-Month-Old Daughter Has 'Rare and Aggressive Form' of Leukemia The update comes a day after Cain shared on social media that his daughter "had relapsed and her leukemia had returned." In an Instagram post about his baby girl's condition, Cain said that the family had found a stem cell donor after doctors determined that Azaylia needed a transplant. "It's hard to put into words how grateful we're are for everyone that's supported, shared and registered to be a donor to help save Azaylia's life. Thank you to EVERYONE! It's truly overwhelming!" Cain began. "However, after Azaylia's second round of chemotherapy, we were informed that Azaylia had relapsed and her leukemia had returned," he continued. "Which highlights how aggressive her cancer is and shows how crucial this transplant will be. It also means she will have to go into transplant with Leukaemia, which is far from what we wanted." The Challenge's Ashley Cain Gives Update on Daughter After Revealing She Has Leukemia Cain went on to explain that the family "were also told that because of her age and the aggressiveness of her cancer, she is in the high risk category for transplant complications and the poor risk category for transplant success." "Hearing that news was absolutely devastating and has made everyday 10x harder for us and hurt even more than it already did!" he wrote. "We go into transplant tomorrow for 4 to 9 months and have been told that it's going to be incredibly tough, that she is going to be very very poorly and it's going to get a lot worse before it gets better! 😔." However, the Ex on the Beach alum noted that the family is "doing our best to remain strong and positive for our daughter." "She made it past the first stage of treatment against the odds and we truly believe that she will do the same this time around!" the dad wrote. "She is a fighter, she will do this and we will be by her side every step of the way! 💯✊🏾❤️." Never miss a story — sign up for PEOPLE's free weekly newsletter to get the biggest news of the week delivered to your inbox every Friday. Cain first spoke of his daughter's leukemia diagnosis in October, sharing that she has "a very rare and aggressive form" of cancer. "💔 Yesterday I had to go through something no parent in the world should have to go through," he wrote in part on his Instagram. "The single most upsetting, terrifying and heartbreaking experience I have ever been through." Last week, Cain said Azaylia had entered her "3rd and toughest round of chemotherapy yet." "Please keep Azaylia in your prayers," he captioned a photo of himself and his daughter. "LETS GO CHAMP."