Tumor-derived exosomes may contain PD-L1 both on the surface and within; proteins involved in packaging and secretion of exosomal PD-L1 include endosomal sorting complex required for transport (ESCRTs), neutral sphingomyelinase 2 (nSMase2) and Rab27a [35]. The gene discussed is SMPD3; the disease is neoplasm.