Up-regulates the activity of the Rho guanine nucleotide exchange factor ARHGEF18 (By similarity). Involved in the regulation of the circumferential actomyosin belt in epithelial cells (PubMed:22006950). Promotes cellular adhesion, migration and motility in vitro and may play a role in wound healing (PubMed:23664528). May have a role in mediating cytoskeletal changes associated with steroid- induced cell differentiation (PubMed:14521927). {ECO:0000250|UniProtKB:Q9JMC8, ECO:0000269|PubMed:14521927, ECO:0000269|PubMed:22006950, ECO:0000269|PubMed:23664528}. This is the function of EPB41L4B (erythrocyte membrane protein band 4.1 like 4B, Ensembl gene identifier ENSG00000095203).