CHMP1A, B2M, and RSU1 loss alterations were significantly enriched in RB1-loss primary tumors at a frequency of 7%–18% above RB1-WT primary tumors and were significantly enriched in RB1-loss metastatic tumors at a frequency of 16%–23% above RB1-loss primary tumors (Figure 5B). This evidence concerns the gene RSU1 and metastatic neoplasm.