Other mechanisms of radioresistance involve growth factors in the tumor microenvironment that have a pro-survival effect, for example, CXCL1, which activates extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) and thus has a pro-survival effect on cancer cells exposed to ionizing radiation [144]. The gene discussed is CXCL1; the disease is neoplasm.