The rif gene family is part of the pir (Plasmodium interspersed repeats) gene super-family of six variant multigene families found in Plasmodium vivax (vir), Plasmodium ovale (oir), Plasmodium knowlesi (kir) and in three rodent malarias (Plasmodium chabaudi, cir; Plasmodium berghei, bir; Plasmodium yoelii, yir). The gene discussed is PIR; the disease is malaria.