In GCEP, similar to CRC the majority of SOX9 mutations were C-terminal truncating exon 3 mutations (truncating mutations: 119/173; 69%; truncating mutations at exon 3; 80/119; 67.2%) (Figure 1D) and more common in antral biopsies compared to body/cardia (Figure S3A; 18.4% vs. 5.1%; Fisher’s test p value 6.9 × 10−12). The gene discussed is SOX9; the disease is colorectal carcinoma.