CA9 and adenocarcinoma: In conclusion, considering all of our results, we can formulate the following hypothesis on the additive effect of RAD001 + volasertib in adenocarcinoma NSCLC PDXs (Figure 7): the combination of RAD001 + volasertib induces, first, an antiangiogenic effect that may result to increase HIF1 expression; this increase of HIF1 expression may induce a decrease of the intracellular pH; in parallel, the combination induces a drop of CAIX protein that is not able to regulate anymore intracellular pH.