Scaffolding protein that regulates epithelial cell polarity by connecting ARF6 activation with the PAR3 complex (By similarity). Plays a redundant role with FRMD4B in epithelial polarization (By similarity). May regulate MAPT secretion by activating ARF6-signaling (PubMed:27044754). {ECO:0000250|UniProtKB:Q8BIE6, ECO:0000269|PubMed:27044754}. This is the function of FRMD4A (FERM domain containing 4A, ENSG00000151474).