Nigerian breast-cancer cohorts exhibit a markedly divergent somatic landscape compared with the TCGA White reference: TP53 is mutated in 58% of Nigerian tumours versus 29% in TCGA White12,13,15, while PIK3CA alterations—though similar to those reported in Kenyan and TCGA Black cohorts—remain substantially lower than in TCGA White16. This evidence concerns the gene PIK3CA and breast cancer.