CD8A and lymphopenia: Importantly, the IRIS-7 randomized, double-blind, placebo-controlled trial in patients with septic shock and profound lymphopenia showed that intramuscular CYT107 was safe, induced a 3–4-fold expansion of circulating CD4+ and CD8+ T cells, and enhanced ex vivo interferon-γ production without causing sustained hemodynamic instability; the main adverse events were injection-site reactions and transient pyrexia associated with modest cytokine elevations [107].