CD4 and monocytic leukemia: We tested this scenario in an allogeneic coculture of CD4+ T-blasts from P2, P3, P4, or healthy donors with THP-1 cells (a monocytic leukemia cell line) or PMA-differentiated THP-1-derived macrophages (P-Mφ), with or without HKMTb (Fig. 4D).