In relation to PTX + MG132-treated U937 culture cells antiapoptotic genes BCL-XL, MCL-1, and Survivin were downregulated as well as the NF-κB-related genes IκB and p65. In general, with these treatment schedules the data suggest a balance in favor of proapoptotic genes in U937 human leukemia cells treated with PTX + MG132. Here, MCL1 is linked to leukemia.