TGFB1 and chronic myelogenous leukemia, BCR-ABL1 positive: Whereas D-PLA detected total phosphorylation of Smad3 at Thr179, Ser204, Ser208, Ser213 and Ser423/425 in TGF-β-treated LT-CML stem cells, as expected (Supplementary Fig. 8), freshly purified LT-CML stem cells showed canonical Smad3 phosphorylation at Ser423/425 and non-canonical phosphorylation only at Ser208 (Fig. 3c,d).