VSIR and choriocarcinoma: Among 112 GTNs (68 choriocarcinomas, 22 PSTTs, and 11 ETTs), Zong et al. [90] reported high levels of PD-L1, PD-L2, and B7-H3 in all samples, and the highest expression of VISTA (V-domain immunoglobulin suppressor of T cell activation), all of which are important component of immunosuppression in the tumour microenvironment.