Essential for the regulation of ciliary length and required for the long-term survival of photoreceptors (By similarity). Phosphorylates FZR1 in a cell cycle-dependent manner. Plays a role in the transcriptional coactivation of AR. Could play an important function in spermatogenesis. May play a role in chromosomal stability in prostate cancer cells. {ECO:0000250, ECO:0000269|PubMed:12084720, ECO:0000269|PubMed:16951154, ECO:0000269|PubMed:21986944}. This is the function of MAK (male germ cell associated kinase, ENSG00000111837).