RNA interference (RNAi) uses small RNA molecules to silence genes and is widely used in biological research. Moffat et al. developed lentiviral shRNA libraries targeting transcription factor regulators, accessible via the GPP Web Portal. These shRNAs specifically reduce mRNA expression, decreasing protein production and inhibiting target gene function. Unlike CRISPR, RNAi provides a reversible method for regulating gene expression, ideal for time-dependent or long-term studies.