G-CIMP tumors were found to belong to the proneural gene expression subtype of gliomas (Noushmehr et al., 2010; Verhaak et al., 2010), and, interestingly, a mathematical model of GBM evolution suggested that most non-G-CIMP mesenchymal GBMs evolve from a proneural-like precursor downstream of chromosome (chr) 7 gain and chr10 loss, followed by CDKN2A loss and/or TP53 mutation (Ozawa et al., 2014). The gene discussed is CDKN2A; the disease is glioblastoma.