RARB and non-small cell lung carcinoma: The combining estimates of the odds ratio from 5 studies having 232 and 213 NSCLC with and without smoking history is OR = 2.46, 95% CI = 1.54-3.93, p = 0.0002, shows RARβ hypermethylation significantly increased in smoking NSCLC patients compared to non-smoking NSCLC.