In pre-planned secondary analyses, we show that cancers with HR deficiency can be robustly identified with the mutational-signatures based classifier HRDetect (Fig. 2 and Supplementary Fig. 1), which identifies cancers with a functional deficiency in HR (Fig. 3b), and with evidence of activity of PARP inhibitors restricted to these cancers using ctDNA analysis (Fig. 3c). Here, PARP1 is linked to cancer.