TTF1 and Merkel cell skin cancer: Considerably, fewer authors analyzed TTF-1 expression in non-pulmonary/non-thyroidal cancers and reported—for example, TTF-1 positivity in 23–75% of endometrioid carcinomas of the ovary [29, 30], 5–80% of serous carcinomas of the endometrium [29, 30], 0–80% of Merkel cell carcinomas [31, 32], and 7–25% of endometrial clear cell carcinomas [29, 30].