In contrast, after Encorafenib pre-treatment, PHI1 exhibited sub-micromolar p-ERK inhibition in both H2087 (IC50 = 485 nM) and H166 (IC50 = 590 nM) lung cancer cell lines, with more prominent effect in H2087, suggesting a strong positive co-operativity of PHI1 within non-V600E-mutated BRAF dimers present in these cells46 (Fig. 7a, b). This evidence concerns the gene MAPK1 and lung cancer.