CD22 and precursor B-cell acute lymphoblastic leukemia: B-ALL cases showed expression of CD79a (99.8%) and CD19 (99%), which is consistent with published literature17 and WHO also assigned CD19 with co-expression of CD79a, CD22 and CD10 for B-lineage.2 Studies reported CD19 as the most sensitive marker in diagnosing B-ALL,20,21 whereas Tong et al. reported CD79a as the most often expressed antigen17 in concordance to our study.