The function of MARCHF2 (membrane associated ring-CH-type finger 2, Ensembl gene identifier ENSG00000099785) is as follows. E3 ubiquitin-protein ligase that may mediate ubiquitination of TFRC and CD86, and promote their subsequent endocytosis and sorting to lysosomes via multivesicular bodies. E3 ubiquitin ligases accept ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and then directly transfer the ubiquitin to targeted substrates (PubMed:14722266, PubMed:16428329). Together with GOPC/CAL mediates the ubiquitination and lysosomal degradation of CFTR (PubMed:23818989). Ubiquitinates and therefore mediates the degradation of DLG1 (PubMed:17980554). Regulates the intracellular trafficking and secretion of alpha1-antitrypsin/SERPINA1 and HP/haptoglobin via ubiquitination and degradation of the cargo receptor ERGIC3 (PubMed:31142615). Negatively regulates the antiviral and antibacterial immune response by repression of the NF-kB and type 1 IFN signaling pathways, via MARCHF2-mediated K48-linked polyubiquitination of IKBKG/NEMO, resulting in its proteasomal degradation (PubMed:32935379). May be involved in endosomal trafficking through interaction with STX6 (PubMed:15689499). {ECO:0000269|PubMed:14722266, ECO:0000269|PubMed:15689499, ECO:0000269|PubMed:16428329, ECO:0000269|PubMed:17980554, ECO:0000269|PubMed:23818989, ECO:0000269|PubMed:31142615, ECO:0000269|PubMed:32935379}. (Microbial infection) Positively regulates the degradation of Vesicular stomatitis virus (VSV) G protein via the lysosomal degradation pathway (PubMed:29573664). Represses HIV-1 viral production and may inhibit the translocation of HIV-1 env to the cell surface, resulting in decreased viral cell-cell transmission (PubMed:29573664). .