SLC7A1 and neoplasm: By analyzing mutational signatures separately in ERR and LRR, we can explore which signatures are biased towards a specific RT region (see “Methods”) In total, 1192 and 176 samples from Mixed cohort and Moore et al., respectively, passed the inclusion criteria for mutational signatures and downstream analyses (at least 50 mutations both in ERR and in LRR; cosine similarity of at least 80% of the tumor mutational profile and the reconstructed profile; see “Methods”).