MAPK8 and monocytic leukemia: They also transfected THP-1 cells with TM plasmid and found that the forced expression of TM increased the percentage of THP-1 cells that expressed CD14, which resulted in the up-regulation of p-JNK, VDR, and C/EBPα in these cells, supporting the idea that TM is a positive regulator of monocytic leukemia cell differentiation.