Additionally it has been shown that loss of function RUNX1 somatic mutations occur at a higher rate in estrogen receptor (ER) positive breast cancers, rather than ER negative breast cancers (Ariffin, 2022; Koboldt et al., 2012), further linking this TF to tumor suppressor activity in hormone receptor (HR) positive breast cancers. The gene discussed is NR4A1; the disease is neoplasm.