Although the pir (Plasmodium interspersed repeats) multi-gene family is unique to P. vivax, P. knowlesi and the rodent clade of malaria parasites without any significant sequence similarity in the P. falciparum genome [43], the reprogramming of antigenic variant gene expression by vector transmission seems to be universal in the Plasmodium genus [29,42,44,45]. This evidence concerns the gene PIR and malaria.