COL17A1 and skin reaction: Various autoantibodies have been suggested as potential biomarkers of irAEs, such as myositis (anti‐acetylcholine receptor antibodies),27 thyroiditis (antithyroglobulin, antithyroid peroxidase),23, 28 hypophyitis (anti‐GNAL, anti‐ITM28),29 pneumonitis (anti‐CD74),29 or skin reactions (anti‐BP180).30