In glucose-deprived cancer cells, SAICAR accumulation was shown to activate PKM2, and a number of other kinases, to promote cancer survival in glucose-limiting conditions, suggesting that purine metabolite accumulation could have distinct signaling outcomes that impact on cell behavior and fate during development (Keller et al., 2012; Keller et al., 2014; Yan et al., 2016). Here, PKM is linked to cancer.