The function of Ensembl gene identifier ENSG00000109083 (IFT20, intraflagellar transport 20) is as follows. Part of intraflagellar transport (IFT) particles involved in ciliary process assembly (PubMed:17604723). May play a role in the trafficking of ciliary membrane proteins from the Golgi complex to the cilium (PubMed:16775004). Regulates the platelet-derived growth factor receptor-alpha (PDGFRA) signaling pathway. Required for protein stability of E3 ubiquitin ligases CBL and CBLB that mediate ubiquitination and internalization of PDGFRA for proper feedback inhibition of PDGFRA signaling (PubMed:29237719). Essential for male fertility. Plays an important role in spermatogenesis, particularly spermiogenesis, when germ cells form flagella. May play a role in the transport of flagellar proteins ODF2 and SPAG16 to build sperm flagella and in the removal of redundant sperm cytoplasm (By similarity). Also involved in autophagy since it is required for trafficking of ATG16L and the expansion of the autophagic compartment (By similarity). {ECO:0000250|UniProtKB:Q61025, ECO:0000269|PubMed:16775004, ECO:0000269|PubMed:17604723, ECO:0000269|PubMed:29237719}.