The deletion of the Sept4 gene in male mice resulted in infertility due to immotility and morphological defects of spermatozoa, including loss of the annulus, abnormal organization of the mitochondria, the disjunction of midpiece and principal piece, and abnormal bending of the flagellum forming a hairpin‐like structure.21, 22. Here, SEPTIN4 is linked to Infertility.