<prompt> Answer this question truthfullyWhat are the typical characteristics of B-cell acute lymphoblastic leukemia B-ALL lymphoblasts, in terms of their expression of certain markers?  <response>: <reason> As per the information provided, B-ALL lymphoblasts are usually characterized by their expression of CD10, CD19, and CD20, and by being TdT positive for terminal deoxynucleotidyl transferase. 