Furthermore, we confirmed a greater MEK activation in the different tumours developed in a high-MAP3K8 PDX model (PDX1) compared with tumours from a low-MAP3K8 PDX model (PDX2) (Fig. 5d,e right panel), with a positive correlation between MAP3K8 protein level and MEK activation (Fig. 5f). Here, MAP2K7 is linked to neoplasm.