According to the family and her doctors, the Neuroblastoma is believed to be growing in her abdomen for about 10 months now.
In order to meet the said pre-requisites, the blood donation organisation has made a decision to expand its search across the globe with an aim to raise 7-10 donors to donate blood over the period of Zainab's treatment.
Florida-based OneBlood says the donors must have "A" or "O" type blood and be Pakistani, Indian or Iranian; and that even within these ethnic groups, fewer than 4 percent of people have the genetic variation.
A donor's birth parents must both be 100% Pakistani, Indian or Iranian.
"We were all crying", Raheel Mughal, the girl's father, said, according to the Miami Herald.
The cancer can spread to tissues beyond the original site, including bone marrow, bone, lymph nodes, liver and skin. Around 800 new cases are diagnosed in the United States every year.
Mughal said his daughter's diagnosis was "the worst thing" they could have expected, until doctors discovered another problem. OneBlood says her dire situation is complicated by her blood type since she is missing a common antigen that most people carry in their red blood cells.
A toddler in Florida has spurred a hunt for compatible blood donors, and the requirements are incredibly rigid.
Statistically, donors need to be exclusively of Pakistani, Indian or Iranian descent.
OneBlood, which runs blood donor centers across the Southeast, is sharing Zainab's story in the hopes more people who meet the specific donor criteria will come forward to donate for the little girl.
To be a donor, a person must have blood type A or O and they must be missing the same antigen - otherwise her body will reject the blood.
"She's going to need to be completely supported by blood donations in order to survive the cancer treatment in order to kill this cancer." said Bright.
OneBlood is coordinating compatibility testing and asks that prospective donors specify that they are looking to donate for Zainab, so the blood can be tagged for testing.
'We need to find more.It's a humble request, and I request it from my heart, ' said Raheel Mughal said in the video.
"What you're doing to save a human life, my daughter's life, is unbelievable", shared Mughal.