TTF1 and Merkel cell skin cancer: For example, cytokeratin AE1/AE3, CK20, and PAX5 immunostains were ordered on aspirated material from parotid gland of a patient previously diagnosed for Merkel cell carcinoma to confirm a metastatic process or TTF‐1 and Napsin‐A were reviewed to rule out a metastatic lung adenocarcinoma.