Figure 5.
Possible model showing the cooperation of the activating mutations KRAS G12A and BRAF V600E in the present case of lung squamous cell carcinoma (LSCC). Simultaneous activation of the MEK/ERK signaling pathway by CRAF and BRAF occurs individually. BRAF V600E can transphosphorylate and hyperactivate CRAF in the presence of oncogenic KRAS, thus strongly augmenting MEK/ERK signaling activation. ERK-mediated negative feedback is highly resisted by BRAF-V600E.