In terms of the first-line anti-EGFR therapy group, PFS (Fig. 1a: 10.1 months vs 6.8 months, HR: 0.67, 95% CI: 0.46–0.89, P = 0.007), OS (Fig. 1b: 38.3 months vs 27.8 months, HR: 0.62, 95% CI: 0.44–0.88, P = 0.008), and ORR (Fig. 2g: 66% vs 43%, P = 0.002) were significantly higher in the left-sided CRC group than in the middle/low rectal tumour group. Here, EGFR is linked to colorectal carcinoma.