Co-occurring MASP1 alleles increase susceptibility to PF (not necessarily within the same haplotype): rs13094773*A combined with rs3864098*C (OR = 2.51 [95% CI = 1.26–4.97], p = 0.0063), rs13094773*A, and rs698104*T (OR = 2.37 [95% CI = 1.22–4.59], p = 0.0074) and between rs3864098*C and rs698104*T (OR = 1.67 [95% CI = 1.09–2.55], p = 0.0141). Here, MASP1 is linked to pemphigus foliaceus.