In line with this fact, the expression of FH and TEKT1 is lower in semen samples with poor sperm motility (asthenozoospermia)26, indicating that SPANX-A/D family, through the interaction with both proteins FH and TEKT1, could be essential in human spermatozoa to meet energy demands for motility. This evidence concerns the gene SPANXA1 and Reduced sperm motility.