In line with this, an association between mitochondrial dysfunctionality and male infertility as a result of a diminished sperm motility has been reported for several knockout models (VPS13A, Tppp2, Gykl1, and Gk2) (Chen et al., 2017; Nagata et al., 2018; Zhu et al., 2019). The gene discussed is TPPP2; the disease is male infertility.