To our knowledge, only one screening study has addressed the expression of APLN (but not APLNR) in ccRCC tumour tissue and adjacent normal tissue, with the only finding that APLN mRNA expression was higher in tumour tissue.12 In our study we have used three well-characterised cohorts of patients to perform a comprehensive evaluation of mRNA and protein expression of APLN and APLNR in primary RCC tumours and to correlate tumour characteristics and patient survival. This evidence concerns the gene APLN and nonpapillary renal cell carcinoma.