MAP2K7 and neoplasm: In parallel, two of the most highly upregulated genes in RAF/MEK inhibitor-treated BPN tumor cells were Pgc and Cym (Figure 6A, Figure 4—figure supplement 1D), which encode digestive enzymes normally expressed in chief cells found at the base of the stomach gland (Han et al., 2019; Leushacke et al., 2017; McCracken et al., 2017).