Among histiocytic disorders, the immunophenotypic profile for hemophagocytic histiocytic sarcoma is IBA-1+, CD204+, MHC-II-, E-cadherin-; for HS, Reactive histiocytosis and FPH, it is IBA-1+, CD204±, MHC-II+, E-cadherin-; and in histiocytoma and cutaneous Langerhans cell histiocytosis (including feline pulmonary form) it is IBA-1+, CD204±, MHC-II+, E-cadherin+. The gene discussed is MSR1; the disease is familial progressive hyperpigmentation.