Human IQ motif containing G (IQCG) gene was first reported to be involved in the chromosome translocation in a case of acute T-lymphoid/myeloid leukemia. The expression of Iqcg is prominently enriched in the testis of mice and reveals an ordered expression pattern during spermatogenesis. Iqcg knockout (KO) mice are sterile, due to the severe malformation and total immobility of their spermatozoa. The axoneme in the KO sperm flagellum is disorganized and hardly any typical normal "9+2" pattern, composed of two central microtubules surrounded by nine microtubular doublets, could be found in the KO spermatids. However, the cilia structures in the trachea and oviduct, as well as histological appearances of other major tissues, remain unaffected in the KO mice, suggesting Iqcg's specific role in spermiogenesis (PMID: 24849454).