Inhibiting only three proteins, interferon-β, STAT2, and EIF2AK2 is sufficient to rescue human fibroblasts from the cell death caused by frequent transfection with long, protein-encoding RNA. Inhibiting interferon signaling disrupts the positive-feedback loop that normally hypersensitizes cells exposed to exogenous long RNA.  Researchers have recently used this technique to express reprogramming proteins in primary human fibroblasts.