HLA-DRB1 and acute lymphoblastic leukemia: For the ALL peptide pool the median numbers of predicted strong binding pMHC complexes per allotype were 243 for HLA-A (range, 167 to 377), 208 for HLA-B (range, 135 to 325), 246 for HLA-C (range, 217 to 340) summing up to 1,482 for HLA class I (range, 1,122 to 1,836), and 358 for HLA-DRB1 (range, 59 to 661) (see Figure 4).