Interestingly, CD74 protein was found in subsets of fibroblasts in prurigo nodularis, a chronic skin condition characterized by very itchy, firm lumps [31], and in a subset of antigen-presenting fibroblasts in lupus erythematosus, a chronic disease that causes inflammation in connective tissues (Table 3) [32]. This evidence concerns the gene CD74 and lupus erythematosus.