SMARCA4 and neoplasm: In the TRACERx cohort, in addition to truncal TP53 and KRAS driver mutations, truncal SMARCA4 mutation, truncal CCNE1 amplification, and truncal loss/LOH of chromosome 21q were associated with predominantly high-grade pattern tumours, while truncal gains of 1q and 8q were associated with predominantly low/mid-grade tumours (Fig. 1d).