Another group found that IL-4 and IL-6 accentuated galactose deficiency of IgA1 through inhibition of C1GALT1 and indirect upregulation of ST6GALNAC2, which blocks galactosylation by C1GALT1, contributing to reduced galactosylation of the O-glycan in IgAN [89]. This evidence concerns the gene C1GALT1 and hyperinsulinemic hypoglycemia, familial, 4.