Increased expression of these keratins in HS lesions is not due to the number of eccrine sweat glands in the adnexal and inguinal regions, where HS is often found; keratin 77, which is exclusively expressed in eccrine sweat glands, is here shown to be decreased in HS lesions (Table 4) [65]. The gene discussed is KRT77; the disease is histiocytic sarcoma.