To examine whether ectopic expression of necdin promotes degradation of endogenous PIAS1, we infected H1299 cells, a human non-small cell lung carcinoma cell line that endogenously expresses PIAS1 at a relatively high level, with necdin-expressing lentivirus vector and analyzed the PIAS1 level by Western blotting (Fig. 6). Here, PIAS1 is linked to non-small cell lung carcinoma.