Microtubule inner protein (MIP) part of the dynein-decorated doublet microtubules (DMTs) in sperm flagellar axoneme, which is required for motile flagellum beating (By similarity). Forms an extensive interaction network cross-linking the lumen of axonemal doublet microtubules (By similarity). . This is the function of Ensembl gene identifier ENSG00000160994 (TEKTL1, tektin like 1).