May play a role in photoreceptor function. In the retinal photoreceptor cells, localizes at the connecting cilium, a thin bridge linking the cell body and the light-sensing outer segment. Expression is low to moderate in retina and tissues, such as heart and kidney, and is predominantly expressed in brain. Abundantly expressed in the retina, compared with only minimal expression in brain and other tissues. O-glycosylated. O-mannosylated by POMT1 and POMT2 and elongated by POMGNT1. The disease is caused by variants affecting the gene represented in this entry. A chromosomal aberration involving KIAA1549 is found in pilocytic astrocytoma. A tandem duplication of 2 Mb at 7q34 leads to the expression of a KIAA1549-BRAF fusion protein with a constitutive kinase activity and inducing cell transformation. Produced by alternative promoter usage. Produced by alternative promoter usage. Belongs to the UPF0606 family. Extended N-terminus.