NR4A1 and neoplasm: Regarding ER(+) and/or PR(+) cancers, the 2010 ASCO/CAP guidance notes that hormone receptor positivity is defined as nuclear immunohistochemical staining for ER and PR that is greater than or equal to 1%, which indicates that the tumor is sensitive to anti-oestrogen therapy, that the tumor is treatable by endocrine therapy, and that the overall prognosis is good.