Later studies revealed other genetic causes of sperm-related human infertility, including homozygous pathogenic variants in the actin-like 9 (ACTL9) gene [31], disruption of the IQ motif-containing N (IQCN) gene [32], and bi-allelic mutations in PLCZ1 (the gene coding for PLCζ in humans) [33,34]. This evidence concerns the gene ACTL9 and Infertility.