Microtubule inner protein (MIP) part of the dynein-decorated doublet microtubules (DMTs) in cilia axoneme, which is required for motile cilia beating (By similarity). May play a role in the beating of primary cilia and thereby be involved in the establishment of organ laterality during embryogenesis (PubMed:26531781). Interacts with PIERCE1 and PIERCE2; the interactions link outer dynein arms docking complex (ODA-DC) to the internal microtubule inner proteins (MIP) in cilium axoneme. Expressed in skin fibroblasts (at protein level). The disease is caused by variants affecting the gene represented in this entry. Belongs to the CFAP53 family. Truncated N-terminus.