The Rab27a mutation that impairs both the exophilin-4 and Munc13-4 interactions but retains the melanophilin interaction causes hemophagocytic lymphohistiocytosis without albinism (Ohishi et al., 2020), which suggests that, in contrast to melanophilin, exophilin-4 is dispensable for melanosome transfer to keratinocytes. The gene discussed is UNC13D; the disease is hemophagocytic syndrome.