We further analyzed the relationship between ID and OOD performance at the individual data set level (Table ) and found a more nuanced relationship across data sets. Taking max dissimilarity splitting as an example, we have seen varying correlations: positive correlation for HERG (in both Classical ML and GNNs), negligible correlation for CYP2C19, and negative correlation for CYP3A4 (Figure ). Three key factors contribute to the diverse patterns.