CD4 and neoplasm: Having established that CD4+ T-cells promote PD-L2 expression in Panc47 FAK-wt tumours and that IL6 present in FAK-wt CM can enhance IL4-dependent expression of PD-L2, we next sought to determine whether IL6 secreted by PDAC cells was also important for Panc47 tumour growth and PD-L2 expression in vivo.