MMP2 and nonpapillary renal cell carcinoma: In order to develop a treatment plan for patients with IS1 ccRCC, we analyzed the receptors and drug targets of these signaling pathways, and found that E-cadherin, MMP2, MMP3, and VIM were significantly highly expressed in the IS1 subtype, while TJP1 (ZO-1) had significantly lower expression (Figure 6D–6H).