ITGB1 and acute lymphoblastic leukemia: Moreover, the expression level of specific surface markers such as CD90, CD29, CD105, and CD166 decreased with passaging (Fig. 2b), especially the surface marker CD90, with the expression reduced from 94.85 ± 4.81% (ALL MSCs) and 95.85 ± 1.18% (AA MSCs) at P4 to 18.33 ± 1.13% and 4.69 ± 0.48% at P10 (P < 0.05) (Fig. 2b).