RGS1 and nonpapillary renal cell carcinoma: PFS also did not achieve statistical difference RGS1 expression groups, and at the latter stages of the disease, in comparison to the low RGS1 expression group, PFS was greater in the group with high RGS1 expression (Fig. 3C), indicating that RGS1 might have a multifaceted role in ccRCC and potentially act as a protective factor later on.