KLF4 significantly reduced the fraction of cells in S-phase, accompanied and eventually caused by upregulation of the bona fide KLF4 target gene p21 (Figs. 3e and Supplementary Figure S6E and Table S2), but also induced cleavage of PARP and caspase-3 (Fig. 3f and Supplementary Figure S6F) indicating that KLF4 impaired tumor growth by inducing cell cycle arrest and apoptosis. The gene discussed is CASP3; the disease is neoplasm.