PTCH1 and hepatocellular carcinoma: We then examined levels of CD44 and Hedgehog signaling proteins (Ptch1, Shh and Gli1) in HCC cell lines grown in a monolayer or in a spheroid condition by Western blot analysis and found that levels of CD44 and Hedgehog signaling proteins were higher in the spheroid cells than in the monolayer cells (Fig. 7d).