The function of KCNV1 (potassium voltage-gated channel modifier subfamily V member 1, Ensembl gene identifier ENSG00000164794) is as follows. Potassium channel subunit that does not form functional channels by itself. Modulates KCNB1 and KCNB2 channel activity by shifting the threshold for inactivation to more negative values and by slowing the rate of inactivation. Can down-regulate the channel activity of KCNB1, KCNB2, KCNC4 and KCND1, possibly by trapping them in intracellular membranes. {ECO:0000269|PubMed:8670833, ECO:0000269|PubMed:9079713}.