NR4A1 and cancer: However, establishing PDXs can take anywhere from several months to more than a year, and depends on a variety of factors, such as the cancer (sub)type, the quantity and quality of the tumor sample, the implantation technique, the implantation site, the immunodeficient mouse strain as well as supplementation of human factors (e.g., hormones for hormone receptor-positive cancers) (Figure 2B) [60,61,62].