To gain insight into the mechanism underlying TCF7L1’s ability to increase tumor incidence and progression in the mouse model of skin SCC, we examined TCF7L1’s effect on oncogene-induced senescence (OIS), as senescence represents an early tumor suppressive barrier that must be overcome for tumor development to occur (Collado and Serrano, 2010). The gene discussed is TCF7L1; the disease is neoplasm.