ERBB4 and metastatic neoplasm: For metastatic tumors from GENIE, a total of sixteen candidate genes had significantly higher SNV frequencies in MMR-d tumors, of which six genes (KMT2D (33.3%), JAK1 (28.3%), FAT1 (21.7%), ERBB4 (20.0%), KMT2A (20.0%), and MGA (20.0%)) had a SNV frequency ≥ 20% in MMR-d tumors.