Inositol 4-phosphatase which mainly acts on phosphatidylinositol 4-phosphate. May be functionally linked to OCRL, which converts phosphatidylinositol 4,5-bisphosphate to phosphatidylinositol, for a sequential dephosphorylation of phosphatidylinositol 4,5-bisphosphate at the 5 and 4 position of inositol, thus playing an important role in the endocytic recycling (PubMed:25869669). Regulator of TF:TFRC and integrins recycling pathway, is also involved in cell migration mechanisms (PubMed:25869669). Modulates AKT/GSK3B pathway by decreasing AKT and GSK3B phosphorylation (PubMed:17322895). Negatively regulates STAT3 signaling pathway through inhibition of STAT3 phosphorylation and translocation to the nucleus (PubMed:25476455). Functionally important modulator of cardiac myocyte size and of the cardiac response to stress (By similarity). May play a role as negative regulator of axon regeneration after central nervous system injuries (By similarity). a myo-inositol phosphate + H2O = myo-inositol + phosphate Homodimer (PubMed:25869669). Interacts with OCRL and RAB5A (PubMed:25869668). Interacts with INPP5B and INPP4A (PubMed:25869668). Interacts with STAT3; the interaction is independent of STAT3 'TYR-705' phosphorylation status (PubMed:25476455). Also found on macropinosomes. Ubiquitous (PubMed:11274189). Highly expressed in brain (PubMed:26203138). INPP5F has been initially described as an inositol polyphosphate 5-phosphatase. Extended N-terminus.