Despite efficient labeling of K-Ras-G12D by G12Di-4–6 in cells, these compounds did not show significant mutant selectivity in terms of cell growth inhibition in a survey of seven cancer cell lines including three KRASG12D mutant lines and four with either WT KRAS or non-G12D KRAS mutations (Extended Data Fig. 5a,b). Here, KRAS is linked to cancer.