IGF1 and cancer: IGF‐1R is upregulated in most malignant tumors, and its combination with the ligands IGF‐1 or IGF‐2 can activate the PI3K/AKT and Ras/Raf/MEK/ERK/MAPK signaling pathways, thereby promoting tumor proliferation, differentiation, and migration and playing a role in fine‐cell apoptosis inhibition.