Recent studies have shown an association between increased miR‐34b‐3p expression and early fibrosis in HBV‐infected liver disease.15 miR‐34b‐3p is down‐regulated in small‐cell lung cancer and is a candidate antitumour miRNA.11 MicroRNA‐34b potently inhibited migration and invasion in metastatic prostate cancer cells by regulating the TGF‐β pathway.12 MicroRNA‐34b acted as a tumour suppressor in the oestrogen‐dependent growth of breast cancer cells.13 These findings prompted us to investigate the function and regulatory mechanism of miR‐34b‐3p in NSCLC cells. The gene discussed is TGFB1; the disease is Familial prostate cancer.