RARB and non-small cell lung carcinoma: That is the RARβ conveyed the positive association for promoter hypermethylation when comparing NSCLC tumors to normal controls, with the pooled OR of 6.05 (95% CI = 3.56-10.25, p < 0.00001) from 7 studies having both NSCLC tissues (n = 646) and normal lung tissues (n = 580) (Figure 2).