Microtubule inner protein (MIP) part of the dynein-decorated doublet microtubules (DMTs) in cilia axoneme, which is required for motile cilia beating (PubMed:36191189). Microtubule-associated protein which regulates cell division and neuronal migration during cortical development (PubMed:19734894, PubMed:28370826). Necessary for radial and tangential cell migration during brain development, possibly acting as a regulator of cell morphology and process formation during migration (PubMed:22926142). May enhance calcium influx through CACNA1E and stimulate programmed cell death (PubMed:15258581, PubMed:19734894, PubMed:22926142, PubMed:28370826). {ECO:0000269|PubMed:15258581, ECO:0000269|PubMed:19734894, ECO:0000269|PubMed:22926142, ECO:0000269|PubMed:28370826, ECO:0000269|PubMed:36191189}. This is the function of Ensembl gene identifier ENSG00000096093 (EFHC1, EF-hand domain containing 1).