STAT3 and cholangiocarcinoma: Likewise, the ratios of p-JAK2/JAK2 and p-STAT3/STAT3 in CCA cells pretreated with 75% PA-CM prior to IL-6 treatment decreased significantly compared to CCA cells treated with IL-6 alone (Figure 5E), indicating that PA-CM prevents the IL-6-induced JAK2/STAT3 signaling pathway in CCA cells.