ESR2 and lung cancer: Moreover, the β isoform of ER is expressed in almost 90% of non-small cell lung cancer (NSCLC) samples, while women with ERβ-negative lung cancer had a small reduction in mortality compared to those with ERβ-positive cancer; in men, however, it is the exact opposite, indicating ERβ as a possible tool for the prognosis of NSCLC in males [38].