Taken together, we discuss the idea of a trade-off mechanism, in which the genetic association of PKLR variants, possibly selected for their malaria resistance in Africa, is also associated with susceptibility to mycobacterial diseases and, because of the heterogeneity in the Brazilian population, could be possible to detect selection signatures in the PKLR region among African-descendent populations. The gene discussed is PKLR; the disease is malaria.