In line with this, it has been recently shown that hyper-activated pro-proliferative signaling cascades such as PI3K/mTOR- and MEK-1/ERK-dependent pathways are potently down-regulated in tumor spheroids of colon cancer cells as a large proportion of cells in 3D structures are growth-arrested (Riedl et al, 2017). Here, MAP2K1 is linked to malignant colon neoplasm.