In order to investigate whether direct inhibition of STAT6 signalling can antagonize the effects of IL-4 on the clonogenic potential of primary PCa cells, a selective STAT6 inhibitor (AS1517499) was used at varying concentrations.31 After toxicity testing in primary cells (Figure 6a), two concentrations of the inhibitor (100  and 300 nm) were selected for further use, and their efficacy was verified by Western blot analysis for STAT6 phosphorylation following IL-4 exposure. This evidence concerns the gene IL4 and posterior cortical atrophy.