The aim of our study was, therefore, to assess the OH1-HMGB1-TIM3 activation axis in biopsy samples from cSCC patients affected by RDEB, from primary cSCC in non-RDEB subjects and from pseudoepitheliomatous cutaneous hyperplasia in RDEB patients. This evidence concerns the gene HMGB1 and recessive dystrophic epidermolysis bullosa.