Kopper and colleagues have performed gene editing in normal non-tumor organoids established from fallopian tube or ovarian epithelium using CRISPR-Cas9 gene editing for modelling TP53 mutations, and determined that HRD ovarian cancer organoids with fewer RAD51 loci were more sensitive to the PARPi niraparib, analogous to responses observed in vivo (Kopper et al., 2019). Here, TP53 is linked to neoplasm.