To screen for novel LSC-associated oncogenes, we initially analyzed several AML datasets from the Oncomine [18] and NCBI GEO [17,19] databases and identified serine protease inhibitor Kazal type 2 (SPINK2) with an elevated expression in AML compared to that in other leukemias, particularly in functionally defined LSC fractions (Figure S1). Here, SPINK2 is linked to leukemia.