The native DTX3L‐PARP9 complex from prostate cancer cells, and the complex reconstituted from recombinant proteins, is a multimer which by gel filtration is predicted to contain 5–6 copies of the DTX3L‐PARP9 heterodimer (Ashok et al., 2022; Yang et al., 2017). Here, PARP9 is linked to Familial prostate cancer.