A, Average tumor multiplicity ± SD of peripheral lung tumors in KRasLA2 after two weeks and six weeks of oral nicotine treatment (n=5–7). B, Survival of KRasLA2 mice with or without oral nicotine treatment starting at 6 weeks of age (n=5). C, Representative images of IHC for p-S6, p-Akt, p-Erk and Ki-67 (right). Quantification of IHC (n=5). Columns represent mean staining indices ± SD. For Ki-67, columns represent mean percentage of tumor cells with positive staining ± SD. Unless indicated, any differences are not significant.