B2M mutations were identified in 10 of 34 tumours (29%), none of which recurred during 5 years follow‐up (none of 10), while six of 24 (25%) B2M‐wild‐type MSI‐H CRCs recurred (P = 0.09), all within 12 months of surgery.12 These studies suggested that B2M mutation status might provide useful prognostic information, but were inconclusive because of their small size. Here, B2M is linked to neoplasm.