Recently, our study reported that the hypomethylation in the CpG islands of the miR-224 promoter region increased the expression of miR-224, and promoted tumor progression and metastasis of NSCLC by targeting SMAD4 and TNFα-induced protein 1 (TNFAIP1) (Cui et al., 2015b). The gene discussed is SMAD4; the disease is non-small cell lung carcinoma.