Groups 2 (Mende from Sierra Leone) and 3 (Bambara and Malinke from Mali and Fula II from the Gambia) are discriminated by SNPs associated with chronotype (behavior according to the biological clock), BMI, response to chemotherapy in breast cancer and neurocognitive impairment in HIV-1 (enrichment p value < 0.0001). Here, CLOCK is linked to breast cancer.