THY1 and precursor B-cell acute lymphoblastic leukemia: To develop a mouse model of BALL, in the present study, we first validated human BALL cell-specific detection markers, CD20 and CD38, by immunofluorescence and western blotting and found that CD20 and CD38 were widely expressed in BALL cells whereas the SSC markers CD90 [22–24] and CD49f [14] were not expressed.