SLC6A1 and nonpapillary renal cell carcinoma: For example, SLC6A1 expression in mucosa of atrophic gastritis and duodenal metaplasia were up-regulated by more than 10 times as compared with normal gastric mucosa [16],; SLC6A1 overexpression was reported to promote cell growth and metastasis of clear cell renal cell carcinoma(CCRCC) [17] and was related to drug resistance to topotecan of ovarian cancer cell line [18].