As PC4 activity is regulated by casein kinase II phosphorylation and only the dephosphorylated form of PC4 is functionally active [13–15], the reduced levels of PC4 detected from AG-1031-treated cell lines or animal tissues correspond to the size of unphosphorylated form, We further conclude that PC4 plays an important role in pathogenesis of non-small cell lung cancer and other types of tumors. The gene discussed is SUB1; the disease is non-small cell lung carcinoma.