CPZ and Ewing sarcoma: In agreement with the varied effect of CPZ on MAPK phosphorylation, Martins and coworkers showed that CPZ decreases phosphorylation of ERK1/2 in Ewing sarcoma (ES) cells leading to reduction in cell proliferation and increase in the cell apoptosis levels [92], whereas Lee and coworkers showed that CPZ increased JNK phosphorylation in human colorectal cancer HCT116 cells, causing inhibition of the tumor cell growth and increased apoptosis [93].