Ella Martinez and Kamila Saradpon are all smiles when they're together.
Ella lives in National City and Kamila in Spring Valley but frequent trips to the San Diego Blood Bank keep them close outside of playdates.
The two girls share a unique, and rare, bond: Thalassemia.
"Having Ella has helped Kamila...having someone to look up to. That's her Thalassemia big sister," Kamila's mom, Maria, said.
The blood disorder requires them to receive frequent blood transfusions. A need that could be in short supply over the summer months.
"Summer is always a challenging time for blood centers to ensure an adequate blood supply due to donors taking vacations and schools being out of session. Despite the season, the need for blood remains constant and patients continue to depend on the generosity of blood donors to meet that need," according to the blood bank.
Ella and Kamila often share their positivity with donors, visiting the blood bank and thanking donors in person, a tradition that began with Ella at a Comic-Con blood drive.
"It was such a wonderful experience, you know thanking the people and actually having them kind of face the child...ever since then we've had a really strong bond with the San Diego Blood Bank," Ella's mom, Erica, said.