PKM and cancer: Consistent to this notion, we observed significant enrichment of both pkm2and pkm1isoforms in our Myc/xmrk tumor samples, with a more obvious enrichment of pkm2isoform.Currently, the information on function of PKM1 and PKM2 in different cancers is controversial, as some studies indicated indispensable function of PKM2 in glioblastoma formation [41, 43] while others showed dispensable function of PKM2 in colon cancer maintenance and progression [45].