To identify potential CK2 substrates that can be targeted by CIGB-300 in T-ALL cells, we conducted signaling experiments with antibodies directed against CK2 phosphoacceptor sites in Akt (S129) and PTEN (S380), as well as against B23/NPM1, previously recognized as a major target for CIGB-300 in solid tumors [46]. Here, NPM1 is linked to acute lymphoblastic leukemia.