CYLD is a deubiquitination enzyme that regulates different cellular processes, 
such as cell proliferation and cell survival. Mutation and loss of 
heterozygosity of the CYLD gene causes development of cylindromatosis, a benign 
tumour originating from the skin. Our study shows that CYLD expression is 
dramatically downregulated in basal cell carcinoma (BCC), the most common cancer 
in humans. Reduced CYLD expression in basal cell carcinoma was mediated by 
GLI1-dependent activation of the transcriptional repressor Snail. Inhibition of 
GLI1 restored the CYLD expression-mediated Snail signaling pathway, and caused a 
significant delay in the G1 to S phase transition, as well as proliferation. Our 
data suggest that GLI1-mediated suppression of CYLD has a significant role in 
basal cell carcinoma progression.