SMARCA4 and thoracic cancer: In this context, we highlight our review on the physiopathology of the SWItch/Sucrose Non-Fermenting (SWI/SNF) complex-regulated SMARCA4 gene, the clinicopathological features of SMARCA4-deficient thoracic cancers, the immunohistochemical detection method in SMARCA4-deficient NSCLC, the necessity of molecular testing in SMARCA4-deficient NSCLC, and the potential therapeutic strategies in SMARCA4-deficient NSCLC.