RecruitingPhase 1Biological interventionChimeric Antigen Receptor T Cell Therapy Redirected to CD4 (CD4CAR)as a Second Line Treatment for Chronic Myelomonocytic Leukemia, CMML.This study is designed as a single arm open label traditional Phase I, 3+3, study of CD4-directed chimeric antigen receptor engineered T-cells (CD4CAR) in subjects with relapsed or refractory CMML. Specifically, the study will evaluate the safety and feasibility of CD4CAR T-cells.