IGF1 and cancer: Clinical evidence for IGF-associated immunosuppression comes from reports of low tumor infiltrating lymphocytes (TILs) in high IGF-1R PCa bone metastases, and genomic aberrations in cancer patients with hyper-progressive disease post-ICB, including mutations in negative IGF regulator IGFBP2 and transcriptional upregulation of IGF-1, PI3K-AKT and ERK pathways17,18.