To the editor:I read with great interest the original article by Lee et al. [1] published recently in your most valuable journal entitled "Renal cell carcinoma in kidney transplant recipients and dialysis patients." It seems that the authors believe that routine screening is necessary for renal cell carcinoma (RCC) among patients with end-stage renal disease (ESRD).It is suggested that features such as increasing age, male gender, previous exposure to carcinogens, genetic predisposition, acquired cystic kidney disease (ACKD), and older age of the donor are common and important risk factors for RCC in kidney transplant patients [2,3]. The correlation of ACKD with the occurrence of RCC is stronger in dialysis patients than in kidney transplant recipients [1].It is reported that the prevalence of RCC in the ESRD population is 3% to 4%, and that it is similar in dialyzed and transplanted patients, which corresponds to a rate 100 times that in the general population [4].It is very interesting that clinical, pathological, and outcome features of RCCs arising in native kidneys of transplant patients seem to have many favorable properties when compared with those diagnosed in dialysis patients and patients from the general population. It is unclear whether this behavior is due to particular molecular pathways or to biases in relation to the mode of diagnosis, and this requires further research in the future [4,5].When we focus on the prevalence and behaviors of RCC in ACKD patients, then we can understand why it is recommended in patients with ESRD that screening be performed only in patients with a long life expectancy and minimal major comorbidities with periodic ultrasound examination or computed tomography scans beginning during the third year on dialysis.