However, when cellular PFK-1 activity of the two homogenates made from either cells or tumours was measured in the presence of the adenine nucleotide concentrations that prevailed in vivo in the respective cell types (AMP/ATP ratio of 0.40 for c4 and 0.09 for WT- see Table 3), the PFK-1 activity was two-fold higher (p < 0.001) in the c4 cell homogenate compared to WT and 1.6 fold higher in the tumour homogenates (Figure 4). This evidence concerns the gene PFKM and neoplasm.