Furthermore, pairwise Pearson correlation for 21/33 cancer types revealed recurrent correlation between the expression patterns for multiple class I-III NRs and retinoid X receptors (RXRs), as well as, strong positive correlation between class IV NRs (NR4A1, NR4A2, NR4A3) in 20/21 pan-cancers. Here, NR4A2 is linked to cancer.