Plays a role in primary ciliogenesis by modulating actin polymerization. Interacts with TTC17. Colocalized with TTC17 at F-actin rich zones and at dynamic plasma membrane protrusions. Strongly expressed in round and elongating spermatids, weakly in pachytene spermatocytes. Expressed in Leydig cells (at protein level). Expressed in testis, placenta, prostate and lung, and moderately in ovary and brain. The disease is caused by variants affecting the gene represented in this entry. Belongs to the CATIP family.