In anti-CD3 antibody-stimulated splenocytes, HF alone inhibited T cell proliferation (IC70 = 3.2 nM), and in combination with 1 nM of RAPA the inhibition was significantly increased to 74.0 ± 2.42% in cultures with 0.625 nM of HF or 86.35 ± 2.11% with 5 nM of HF (IC70 = 0.6 nM, n = 5) (HF alone vs. HF + RAPA: P < 0.0001, two-way ANOVA) (Fig 1A). The gene discussed is TRERF1; the disease is hydrops fetalis.