RXR has a vital role in the transcription of tumor suppressor genes which induce differentiation and suppress cancer growth.78, 79 As NR4 subfamily nuclear receptors (e.g., Nur77, NURR1) are ubiquitous heterodimerization partners of RXR in forming heterodimers,80 current study also revealed that when the cancer cells are incubated with HX600, a selective RXR agonist for Nur77-RXR and NURR1-RXR, the expression of CPTIA is induced through Nur77 or NURR1-mediated mechanism in the teratocarcinoma cells or heptoma carcinoma HepG2 cells81 (Figure 3). This evidence concerns the gene NR4A1 and neoplasm.