We developed a novel culture system to obtain multilineage undifferentiated stem/progenitor cells from normal human thyroid tissues. This seems to be achieved by direct reprogramming of thyroid follicular cells. The objective of the study was to reveal gene expression profile of the obtained cells compared to primary thyrocytes. After enzymatic digestion, primary thyrocytes, expressing thyroglobulin and cytokeratin-18, were cultured in a serum-free medium called SAGM containing insulin and EGF. Although the vast majority of cells died, a small proportion (~0.5%) survived and proliferated. During initial cell expansion, thyroglobulin/cytokeratin-18 expression was gradually declined, suggesting that those cells are derived from thyroid follicular cells or at least thyroid-committed cells. The SAGM-grown cells did not express any thyroid-specific genes. However, after four-week incubation with FBS and TSH, cytokeratin-18, thyroglobulin, TSH receptor, PAX8 and TTF1 expressions re-emerged. Moreover, surprisingly, the cells were capable of differentiating into neuronal or adipogenic lineage depending on differentiating conditions.