Essential for male fertility and sperm mitochondrial sheath formation (By similarity). Required for proper mitochondrial elongation and coiling along the flagellum during the formation of the mitochondrial sheath (By similarity). Facilitates the growth and aggressiveness of neuroblastoma cells (PubMed:30026490). Increases the EZH2 activity and H3K27me3 levels in a RBBP4-dependent manner, and facilitates the enrichment of polycomb repressive complex 2 and H3K27me3 on gene promoters, resulting in transcriptional repression of tumor suppressors affecting the proliferation, invasion, and metastasis of tumor cells (PubMed:30026490). Interacts with TBC1D15, TBC1D21, GK2 and IMMT (By similarity). Interacts with VDAC2 and VDAC3 in a TBC1D21-dependent manner (By similarity). Interacts (via ARM domains) with RBBP4 (PubMed:30026490). Testis-specific (PubMed:33536340). Expressed at higher levels in neuroblastoma tissues and cell lines, than those of normal dorsal ganglia (at protein level) (PubMed:30026490). Expressed in breast cancer, colon cancer, hepatocellular carcinoma, lung cancer, pancreas cancer, prostate cancer, renal cancer and gastric cancer, but not in their normal counterparts (PubMed:30026490).