KLK1 and thyroid gland disorder: To validate the results obtained from qPCR analysis and to define the final panel that would yield best diagnostic accuracy, the two best HCA markers (PVALB and KLK1) were tested, in combination with carcinoma markers (DDIT3, ITM1, ARG2 and C1orf24), in an independent set of 82 thyroid paraffin-embedded sections.