Does not function as a copper(1+) importer in vivo (By similarity). However, in vitro functions as a low-affinity copper(1+) importer (PubMed:17617060, PubMed:17944601). Regulator of SLC31A1 which facilitates the cleavage of the SLC31A1 ecto-domain or which stabilizes the truncated form of SLC31A1 (Truncated CTR1 form), thereby drives the SLC31A1 truncated form-dependent endosomal copper export and modulates the copper and cisplatin accumulation via SLC31A1 (By similarity). {ECO:0000250|UniProtKB:Q9CPU9, ECO:0000269|PubMed:17617060, ECO:0000269|PubMed:17944601}. This is the function of Ensembl gene identifier ENSG00000136867 (SLC31A2, solute carrier family 31 member 2).