RGS4 and breast cancer: While RGS4 transcriptional upregulation has been associated with increased viability, invasion, and motility of thyroid cancer, glioma, ovarian ascites, and Tneg breast cancer cells, it has now been shown that RGS4 mRNA and protein levels do not correlate, since (despite high RGS4 transcript levels) RGS4 protein levels must be proteasomally downregulated to enable metastasis [46].