COL17A1 and psoriasis: Nevertheless, Ständer et al. noted that subjects suffering from BP and comorbid psoriasis had lower levels of anti-BP180 NC16A autoantibodies, possibly reflecting the milder erosive phenotype, and also a higher frequency of isolated linear C3 deposits and a lower frequency of linear IgG deposits along the BMZ, detected by direct immunofluorescence microscopy [15].