Associate Professor Yeoh is senior consultant of the Paediatrics Haematology-Oncology division at NUH, and principal Investigator of the study that helped developed a personalised cancer treatment protocol for children with leukemia. The protocol, which improves cure rate and decreases mortality by reducing the side effects of chemotherapy, is cost-effective, avoids the most toxic therapy, and helps to reduce hospital stay from one month to five days. Most importantly, 81% of patients in the test were cured. Yeoh was trained in NUS and NUH, and was Clinical Fellow at the St Jude Children's Research Hospital from 1999 to 2001. He was the first Singapore doctor to receive the American Society of Hematology Merit Award for his pioneering work in gene-expression profiling in leukaemia. He is also a founding member and vice-president of the Bone Marrow Donor Programme, which connects patients who need a bone marrow transplant with matched donors.