CDK4 and gastric cancer: To further ascertain the mechanism underlying IDF-11774-mediated inhibition of gastric cancer cells through HIF-1α downregulation, we measured the expression levels of cell cycle (Cyclin D1, B1, E1, and CDK4), apoptotic cell death (PARP, cleaved PARP, pro-caspase-3, and cleaved caspase-3), and MAPK signaling (ERK1/2, phosphorylated ERK1/2, p38, phosphorylated p38, JNK and phosphorylated JNK) proteins after IDF-11774 treatment.