ESR1 and non-small cell lung carcinoma: Tamoxifen in estrogen receptor-positive breast tumor, Herceptin in Her 2+ breast cancer, epithelial growth factor receptor (EGRF) inhibitors (erlotinib, afatinib, osimertinib, and fefitinib) in non-small cell lung carcinoma (NSCLC), K-ras inhibitors (cetuximab) in colon cancer, B-Raf inhibitors (vemurafenib, dabrafenib, and encorafenib) in melanoma, and gleevec for ABL-BCL (translocation of c-ABL gene sequences from chromosome 9 into the BCR gene on chromosome 22) positive leukemia have been used widely in clinical settings [3].