One plausible explanation is that when anti-VEGF mAb or anti-EGFR mAb alone inhibits tumor growth, it also slightly decreases the expression of IL6 because of destruction of some tumor cells, while anti-VEGF and anti-EGFR antibodies simultaneously suppress tumorigenesis, the surviving tumor cells increase IL6 levels to escape the killing effect. The gene discussed is VEGFA; the disease is neoplasm.