Researchers unveiled an intelligent design framework for adeno‑associated virus (AAV) vectors that dynamically respond to tumor microenvironment cues to improve tumor targeting and reduce off‑target expression. The team demonstrated modular sensors and regulatory elements that activate payloads preferentially in tumor niches, addressing longstanding delivery and specificity limitations for viral gene therapies. The approach leverages transcriptional and post‑transcriptional switches responsive to hypoxia, proteases and inflammatory signals typical of solid tumors. Translational groups and vector manufacturers may use these design principles to accelerate safer in‑vivo gene delivery for oncology indications, and regulators will evaluate how environmental‑responsive control elements affect biodistribution and safety assessments.