We have previously reported on genes whose KO led to asthenozoospermia, such as Tektin 3 (TEKT3) [11], Tektin 4 (TEKT4) [12], T-complex-associated-testis-expressed 1 (TCTE1) [13], and T-complex 11 (TCP11) [14], with each having unique roles in sperm motility. The gene discussed is TEKT4; the disease is Reduced sperm motility.