MUC5AC and cholangiocarcinoma: By categorizing the CCA areas, a significantly higher extent of LIF staining in ‘ductular-like’ than in ‘mucin-producing’ tumoral bile ducts was determined (Supplementary Figure 1A, 1C); in contrast, no significant differences in the extent of LIFR staining were found between the two CCA subtypes (Supplementary Figure 1B, 1C).