Supportive of the suppressive and cytolytic capacity of CAR19 CD4+ Tregs, Locafaro and colleagues enforced IL-10 expression in human CD4+ T cells to generate a type 1 regulatory–like (Tr1-like) cell that was suppressive and yet acquired cytotoxic activity restricted to myeloid cells, including myeloid malignancies. The gene discussed is IL10; the disease is myeloid neoplasm.