A cell living in an oxygen lacking environment is able to "self tune" its metabolic processes to survive in those hostile conditions using glucose more than oxygen for the production of the energy they need. This phenomenon discovered by Pasteur in 1860 is called anaerobic glycolysis. In 1930, Warburg discovered that once the optimal conditions were restored, healthy cells produce ATP again through cell respiration, while carcinogenic cells had definitively changed their metabolism, using glucose as main energy source. This phenomena is called Warburg effect or aerobic glycolysis. Mutation in the metabolism leads cancer cells not only to accelerate their cell cycle and therefore to increase proliferation rate, but those cells also create an acidic environment for healthy cells, thanks to the glycolysis by-product: lactic acid. The high level of lactic acid in the extracellular environment induces necrosis of healthy cells thus amplifying cancer cells invasion capacity. The aim of our work is to study how this "evolutionary" advantage of aerobic glycolytic tumour cells with respect to healthy cells affects tumour heterogeneity and vasculature system formation of a tumour spheroid.