CPAP and thyroid gland papillary carcinoma: To this aim, we first evaluated whether HMGA1b was able to regulate the SPP1 expression by transiently transfecting the papillary thyroid carcinoma cell line B-CPAP, that shows low expression of the SPP1 gene [24], with increasing amount of a vector expressing the HMGA1b protein fused with the HA epitope (HMGA1b-HA).