IL-1β signaling in human TC cell lines. PTC (BCPAP and TPC1) and ATC (8505C and CAL62) cell models grown to confluence under standard conditions were analyzed by specific ELISA kits, following the manufacturer’s instructions, to evaluate (A) the secreted levels of IL-1β (measured in the medium) and (B) levels of IL1 receptor, type I (ILR1) (measured in the cell lysates), phospho-IRAK-1 (p-IRAK1) (a cell-based method), phospho-TAK1 (p-TAK1) (measured in the cell lysates), phospho-IKK (p-IKK) (a cell-based method), and P65 NF-kB (measured in the nuclear extracts). The histograms indicate mean ± SD of three different cultures, and each was tested in triplicate. The inserts represent the original histograms without ATC cells in order to better appreciate changes in PTC cells. ** p < 0.01, *** p < 0.001, and ° p < 0.001.