TRERF1 and hydrops fetalis: To examine the role of cell death in the synergistic interaction of RAPA with HF in the suppression of T cell proliferation, cell apoptosis or viability was examined using FACS analysis in anti-CD3 antibody-stimulated splenocytes treated with various concentrations of HF (0–5 nM) in the presence of 1 nM RAPA or with various concentrations of RAPA (0–100 nM) in the presence of 2.5 nM HF.