RUNX3 and neoplasm: Furthermore, these results also provide a possible explanation as to why K-Ras-activated tumours recur so quickly: cells with K-Ras mutation are selected only if they occur in R-point-disrupted cells, some of which harbour epigenetically inactivated RUNX3. Suppression of K-Ras cannot restore the already silenced RUNX3, and therefore cannot recover the R-point.