Our work not only supports the conclusion that PEP-dependent PGAM1 H11 phosphorylation occurs in PKM2-expressing tumor cells (Vander Heiden et al, 2010) but also provides a more detailed molecular mechanism for PEP-based phosphotransferring to PGAM1 when pyruvate kinase activity of PKM2 is reduced. Here, PKM is linked to neoplasm.