Hi folks, we previously found a group of cells as part of tumor cell heterogeneity that can contribute to drug resistance. We plan to test if those cells can also be found in vivo. Do you think it is necessary to see a significant tumor volume change between drug-treatment CDX mice and PBS-treatment CDX mice? We expect to see the proportion of that group of cells significantly increase after a short period of drug treatment in vivo, and we don't care whether the drug can effectively shrink the tumor volume shortly. Unfortunately, there's not much prior literature on this experiment for us to estimate the treatment time and tumor volume change, so do you think a reasonable short period of treatment, let's say 6 to 12 days, is good enough to robustly say this group of cells has survival advantage on the drug stress over other cells (when the proportion increase significantly compare to PBS-treatment), without the significant decrease of tumor volumes