NR4A1 and cancer: Chloride channel protein 3 (CLCN3) and procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1), with a specific allocation to Group 1, were reported to be involved in cancer cell proliferation and tumor progression [36, 37], whereas MXD1 and NR4A1 are allocated to Group 2 (Fig. 1F).