CD4 and cytomegalovirus infection: This study aimed to assess the HCMV-specific CD4<sup>+</sup> and CD8<sup>+</sup> T-cell responses and their cytokine production (IFNγ, TNFα, IL2) against various HCMV proteins (IE-1, pp65, gB, gH/gL/pUL128L) in solid organ transplant recipients (SOTRs) and hematopoietic stem cell transplant recipients (HSCTRs) with active HCMV infection.