PIWIL2 and cancer: PIWIL2, aka HILI, is a member of PIWI subfamily containing PIWI and PAZ domains, plays crucial roles in self-renew of stem and germ cells, RNA silencing and translational regulation in different organisms during evolution and is ectopically expressed in different cancer cells16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32.