Proposed effector of Rab5 (PubMed:15328530). Binds to phosphatidylinositol 3-phosphate (PI[3]P) (PubMed:15328530). Involved in homotypic early endosome fusion and to a lesser extent in heterotypic fusion of clathrin-coated vesicles with early endosomes (PubMed:15328530). Involved in macropinocytosis; the function is dependent on Rab5-GTP (PubMed:15328530). Required for correct endosomal localization (PubMed:15328530). Involved in the internalization and trafficking of activated tyrosine kinase receptors such as PDGFRB (PubMed:24102721). Regulates the subcellular localization of the retromer complex in a EHD1-dependent manner (PubMed:22284051). Involved in endosome-to-Golgi transport and biosynthetic transport to late endosomes and lysosomes indicative for a regulation of retromer complex-mediated retrograde transport (PubMed:22284051). Required for podocyte migration (PubMed:29959197). {ECO:0000269|PubMed:15328530, ECO:0000269|PubMed:22284051, ECO:0000269|PubMed:24102721, ECO:0000269|PubMed:29959197}. This is the function of ANKFY1 (ankyrin repeat and FYVE domain containing 1, Ensembl gene identifier ENSG00000185722).