In this study, we demonstrate that the EBV LMP1 protein could effectively suppress the expression of the SAP SH2D1A gene in T cells, as previously shown in Burkitt lymphoma cells, 46 at the transcriptional level, and thereby both XLP and sporadic HLH share a common signal pathway, through either the mutation or the LMP1 mediated suppression of the SAP SH2D1A gene, finally leading to overt T cell activation and enhanced Th1 cytokine secretion in response to primary EBV infection cialis tablets for sale