In our study, metastasis was detected in 6 out of 24 chromophobe RCC patients with CD47 staining, in 1 out of 7 papillary type 2 RCC patients, in 2 out of 3 clear cell RCC patients, and in 16 out of 18 unclassified RCC cases. This evidence concerns the gene CD47 and renal cell carcinoma.