GPR55 and cholangiocarcinoma: Figure 3 and Figure 4 show examples demonstrating that improved discrimination between patients can be achieved by using two biomarkers instead of one (compare Figure 3A and Figure 4A). The most promising result so far was achieved using the GPR55 mRNA/CEA mRNA ratio. Analyses of the entire CC population demonstrated that an increased ratio was associated with an increased survival of 14 and 33 months in the high-expression group (GPR55++) compared to the low expression group (GPR55(−−)) when followed for 5 and 12 years, respectively (Figure 4B).