PC and neoplasm: Furthermore, the tricarboxylic acid cycle (Krebs cycle) also has been recently reported as an essential anabolic source of tumor progress, [180,181,182] since pyruvate carboxylase, the enzyme which is responsible for the transformation of oxaloacetate from pyruvate, the last metabolite of glycolysis, has been pointed out as an important key factor in tumor advance [183,184,185].