As part of the intermicrovillar adhesion complex/IMAC plays a role in epithelial brush border differentiation, controlling microvilli organization and length. Plays a role in assembly of the complex (PubMed:26812018). May play a role in cellular response to endoplasmic reticulum stress (By similarity). {ECO:0000250|UniProtKB:Q8K3X6, ECO:0000269|PubMed:26812018}. This is the function of Ensembl gene identifier ENSG00000175311 (ANKS4B, ankyrin repeat and sterile alpha motif domain containing 4B).