SUMO1 and thyroid cancer, nonmedullary, 2: In thyroid tissue, papillary thyroid carcinoma (PTC) had increased SUMO1 and SENP5 expression, follicular thyroid carcinoma (FTC) showed higher SUMO1 levels, and undifferentiated thyroid carcinoma (UTC) exhibited elevated SUMO1, SUMO2/3, UBC9 and SENP5 levels.