To study the biological meaning of the PET quantitative parameters that remained significant in the tumor response prediction models above (TLG, Glycolysis Q1, GLCM Energy at distances of three, five and nine voxels and GLCM IDMN at distance of seven voxels), their correlation with VEGFR-2, Ki-67, COX-2, E-cadherin, p-53, BCL-2, c-erb b-2 was studied using Pearson correlation. The gene discussed is BCL2; the disease is neoplasm.