Since FAT1 mutations are both common in lung cancer and evolutionarily selected before WGD (Fig. 2a–c), we experimentally validated the mitotic defect associated with FAT1 loss using the near-triploid (3N) LUAD cell line PC9 (which harbours an in-frame deletion at exon 19 of the epidermal growth factor receptor-encoding gene) and its isogenic WGD hexaploid (6N) clone12. Here, FAT1 is linked to lung cancer.