SHH and squamous cell carcinoma: Using two well established acquired chemoresistant cancer cells K562/A02, KB/VCR and their respective parental cells human chronic myelogenous leukemia cell line K562, human epidermoid carcinoma cell line KB, we found that the abundance of Hh ligands SHh, IHh and DHh were all obviously elevated when compared to their respective parental cancer cells as revealed by QT-PCR analysis (Figure 1A), suggesting the possibility of cell-autonomous Hh pathway activity harbored by acquired chemoresistant cancer cells.