PFKFB3 and glioblastoma: Fig 4A and 4B (S5 and S6 Appendices) show a significant increase of this PFKFB3 variant on transcriptional (increase by more than 10 times) and translational levels (increase by 400 times in HEK-293 cells and over 3 times in U87 cells). Indeed, we found that elevated levels of PFKFB3-4 affected proliferation and cell viability positively (Fig 4C and 4D). But overexpression of PFKFB3-4 did not influence mRNA levels of PFKFB3-1 and PFKFB3-11, splice variants which are constitutively expressed in glioblastoma cells (Fig 4E).