The tumor volume in brain metastasis was a significant predictor for the PD-L1 status of a tumor in an AI model, with AUC at 0.77 [374]; while, in another study, brain metastasis was a significant predictor of survival, depending on the gene status of EGFR, ALK, and KRAS mutation-positive groups (AUC at 0.977, 0.905, and 0.947, respectively) [290]. The gene discussed is KRAS; the disease is neoplasm.