MAPK1 and cancer: Independent of current first-line regimens and immune checkpoint inhibition, the ubiquitous activation of EGFR and downstream signaling cascades (MAPK1), as well as cell-cycle checkpoint regulation (WEE1-CDK1) revealed by our phosphoproteomic analysis, provide additional therapeutic targets that have been evaluated extensively in other cancer types but minimally in ccRCC (Ascierto et al., 2013; Huang et al., 2008; Matheson et al., 2016; Ravaud et al., 2008).