KRAS and colorectal cancer: Findings of a meta-analysis including ten randomised controlled trials in advanced colorectal cancer showed, although not statistically significant, a trend towards worse PFS in patients with KRAS mutations (HR 1·11, 95% CI 0·97–1·27);17 three of the ten trials showed a statistically significant detrimental effect.3, 18, 19 Drug-specific adverse interactions with oxaliplatin and bevacizumab have been inferred, although on no basis and with no mechanism proposed, and this has led to a supposition that anti-EGFR monoclonal antibodies are better paired with irinotecan than with other drugs.16