Figure 8.

Comparison between$\mathit{B}\mathbf{\left(}{\mathit{r}}_{\mathit{\text{xy}}}^{\mathbf{\ast }}\mathbf{\right)}$ and$\mathit{B}\mathbf{\left(}{\overline{\mathit{r}}}_{\mathit{\text{xy}}}^{\mathbf{\ast }}\mathbf{\right)}$.$B\left(r_{\mathit{\text{xy}}}^{\ast }\right)$ is the bias of the Pearson correlation coefficients estimated directly from the pooled residuals;$B\left({\overline{r}}_{\mathit{\text{xy}}}^{\ast }\right)$ is the bias of the average of correlations between expression residuals within i = 1,19 groups.