Given the chemical similarity between PCN-222 and NU-1000 (Figure ), the observation that NU-1000 is a potentially toxic MOF is certainly interesting. To dig deeper, we, again, performed SHAP analysis to understand features that had large contributions towards the classification (Figure ). The analysis indicates that the -COOH fragments, planarity of the -system, and features corresponding to the polarity (discussed indetail in Figure ) significantly contribute to the toxicity of the linker. Based on the performance of unseen testing data, and these few examples, the model thus proves to be broadly reliable. However, the scarcity of in vivo MOF data prevents rigorous testing.