By integrating multiple transcriptome data and ccRCC scRNA-seq data, we used multiple machine learning methods to screen three biomarkers that are common between T1DM patients and ccRCC patients (KIF21A, PIGH, and RPS6KA2), which are linked to tumor and immune infiltration, and to predict the trajectory and prognosis of T1DM patients and ccRCC patients in an independent validation cluster. The gene discussed is KIF21A; the disease is nonpapillary renal cell carcinoma.