Paired sample analysis demonstrated low FCN1 expression in multiple tumor samples, such as bladder urothelial carcinoma (BLCA), breast invasive carcinoma (BRCA), and colon adenocarcinoma (COAD), while it exhibited high expression in clear renal cell carcinoma (KIRC) (Supplementary Figure S1D). The gene discussed is FCN1; the disease is invasive breast carcinoma.