The function of Ensembl gene identifier ENSG00000133106 (EPSTI1, epithelial stromal interaction 1) is as follows. Plays a role in M1 macrophage polarization and is required for the proper regulation of gene expression during M1 versus M2 macrophage differentiation (By similarity). Might play a role in RELA/p65 and STAT1 phosphorylation and nuclear localization upon activation of macrophages (By similarity). .