Analysis of TCGA tumor data via the GEPIA2 platform revealed correlations between the expression profile of the HCAR3 gene and genes coding kynurenine aminotransferases, enzymes directly involved in KYNA synthesis (CCBL1, AADAT, CCBL2, and GOT2), particularly in tumors stratified by differential HCAR3 expression. The gene discussed is HCAR3; the disease is neoplasm.