UCHL1 and carcinoma: Although de novo expression of UCH-L1 has been observed in different types of malignancies [3,4], the function of UCH-L1 in the development of primary tumors remains unclear [3,5,6]: Overexpression of UCH-L1 in in vivo transgenic mouse models induces lymphomas acting as an oncogene [7,8], while in the cell lines and tissue samples from different primary carcinomas the expression of uch-l1 is frequently silenced by promoter methylation, suggesting its potential role as a tumor suppressor [8,9].