RET and thyroid gland papillary carcinoma: We designed a functional screening using the human papillary carcinoma cell line, TPC1, harboring at the endogenous level the RET/PTC1 (CCDC6-RET) rearrangement [12] and a commercially available siRNA library containing synthetic siRNAs targeting the 518 human protein kinases as well as kinase-related and -associated proteins.