Finally, we identified 45 cancer-associated proteins (CAPs) to be significantly more abundant in diagnosis specimens (n = 6) or relapse specimens (n = 12) compared to non-cancer controls (n = 3) (Supplementary Fig. S13a-d and Supplementary Data S16), including several proteins that are commonly overexpressed in acute lymphoblastic leukemias such as FLT3, CDK6, and EBF115. Here, FLT3 is linked to acute lymphoblastic leukemia.