CD33 and acute myeloid leukemia: To assess the ADCC efficacy of AFM28 against diverse AML and HR-MDS BM samples, allogeneic NK cells from healthy donors were co-cultured with primary BMMC samples from AML (n = 10) and HR-MDS (n = 5) patients containing primary CD34+ CD38+ or CD33+ CD38+ leukemic cells, hereafter referred to as blasts, for 24 h (Supplementary Fig. 2A–C).