To determine whether anti-BP180 IgG concentration is associated with certain lesion types, we analyzed the relationships between anti-BP180 IgG concentration and individual BPDAI components and discovered a moderate correlation with erosions/blisters (r = 0.3402, P = 0.0180), but not urticaria/erythema (r = 0.1261, P = 0.3931), pigmentation (r = 0.2797, P = 0.0542), and mucosal damage (r = -0.0833, P = 0.5734, Fig. S2C), which is consistent with van Beek N’s research21. This evidence concerns the gene COL17A1 and Erythema.