The N-myc downstream regulated gene (NDRG) family is comprised of four members; NDRG1 (also designated Drg1; RTP; rit42; Cap43 and Ndr1); NDRG2; NDRG3 and NDRG4; which share 57-65% homology. The gene encoding NDRG3 maps to human chromosome 20q11 and is predominantly expressed in testis; prostate and ovary; which suggests it may play a role in spermatogenesis.