EGF and non-small cell lung carcinoma: All of the 17 smoking-associated gene coexpressions in NSCLC patients were observed in the cell experiments, except two coexpressions, one between EGF and LTF and one between CRTAC1 and GPRC5C. These two unobserved gene coexpressions could be related to other sources of carcinogens in tobacco, because NNK is only one of the carcinogens in tobacco, among about 54 others (14).