As examples we chose three different drug molecules (Fig. 3): raloxifen, a partial agonist of the estrogen receptor;23,24 ibrutinib, a potent covalent kinase inhibitor (IC50 of 3–6 nM in chronic active BCR signaling B-cell lymphoma25); and a duocarmycin analog, a highly cytotoxic prodrug of a DNA-alkylating agent with IC50 < 1 nM in human bronchial carcinoma cells26. This evidence concerns the gene ESR1 and bronchogenic carcinoma.