Expression changes of Wee1 inhibition signature in xenograft WiDr tumors and their correlation to classical PD marker, pCDC2. Human WiDr colorectal cancer cells were injected subcutaneously into nude rats. After allowing tumors to establish for 8 days, gencitabine and Wee1 inhibitor were administered in the nude rats as described in the legend of Figure 3. At 8 hr post Wee1 inhibitor administration, mRNA from each WiDr xenograft tumor was applied to quantitative RT-PCR analysis. To correlate the phosphorylated-CDC2 and Wee1 gene expression signature, the level of the pCDC2 normalized to total CDC2 is shown. The correlation coefficient (R) of pCDC2 expression and each mRNA expression is shown in each graph. Data represent mean ± SD. **, P < 0.01, compared with gemcitabine treated sample.