CTSD and colorectal carcinoma: The results summarized in Figure 4B demonstrate that LiCl (an inhibitor of GSK3 activity), but not NaCl, increased the inhibiting phosphorylation of GSK3α and 3β (Figure 4B, p-GSK-3α and β), and in LiCl-treated cells there was a further increase in CTSD levels in L1-expressing CRC cells (Figure 4B), implying that Wnt/β-catenin signaling could be the mechanism responsible for increased CTSD expression in LS 174T cells.