ITGB3 and Thrombocytopenia: The lower integrin α2b and β3 (ITGA2B, ITGB3) protein levels found in the MLL-r samples (Supplementary Table 7) is consistent with the presumed BM microenvironment origin of these proteins: they would be expected to be present at lower levels in the BM of leukemia cases, which typically present with thrombocytopenia.