“When I analysed tumour samples from 100 Kenyan cancer patients in our laboratory, I expected to find genetic mutations similar to those documented in Western populations. What I discovered instead would challenge decades of medical assumptions,” writes Dr Mansoor Saleh, founding chair of haematology-oncology at Aga Khan University, Nairobi. “None of these Kenyan cancer patients carried the KRAS G12C mutation, which is found in 3%-15% of Caucasian cancer patients.” This finding represents more than scientific curiosity. It exemplifies a critical fact that cancers diagnosed in African patients may well be different in molecular characteristics than those in Caucasian patients, even when they share the same pathologic diagnosis.