Figure 2. The growth pattern of the xenograft model was correlated with the proliferation of the cell lines. A scatter plot for tumor growth in the xenograft model (doubling time in vivo) versus cell proliferation (doubling time in vitro) was plotted, and correlation analysis was conducted. Tumor growth in the xenograft model (doubling time in vivo) was calculated by using the exponential growth equation (eq. 3). ^* indicates statistical significance at the 5% level.