ID1 and cancer: Based on the biological complexity of the “activating invasion & metastasis” cancer hallmark, we clustered in our in silico analysis a comprehensive set of 194 proteins that are involved in five pathways of the Reactome database (Signaling by MET, R-HSA-6806834.2; Signaling by TGF-beta Receptor Complex in Cancer, R-HSA-3304351.2; TGF-beta receptor signaling in Epithelial to mesenchymal transition, Id: R-HSA-2173791.1; Signaling by NOTCH4, Id: R-HSA-9013694.2 and Signaling by NOTCH3, Id: R-HSA-9012852.2).