As a component of the IFT complex A (IFT-A), a complex required for retrograde ciliary transport and entry into cilia of G protein-coupled receptors (GPCRs), it is involved in ciliogenesis and ciliary protein trafficking (By similarity). May promote CASP3 activation and TNF-stimulated apoptosis (PubMed:20193664). Component of the IFT complex A (IFT-A) complex. IFT-A complex is divided into a core subcomplex composed of IFT122:IFT140:WDR19 which is associated with TULP3 and a peripheral subcomplex composed of IFT43:WDR35:TTC21B. Interacts directy with IFT122, ITF43 and TTC21B. Interacts with IFT43. Expressed at high levels in testis and at lower levels in the brain (at protein level). Also present in other tissues, including heart, uterus, spinal cord, ovary, liver, kidney, lung, pancreas and stomach.