TGM2 and Cowden disease: In the ORA, most of the gene groups identified as differentially expressed between the Anti‐TG2‐based CD diagnosis and Biopsy‐based CD diagnosis groups were linked to retinoid metabolism and response to vitamin A, and in the FGSEA, genes associated with the retinol metabolic process were less expressed in Anti‐TG2‐based CD diagnosis than in Biopsy‐based CD diagnosis.