Find E3 ligases that only tumours have, and build degraders around them

Almost all clinical degraders use cereblon or VHL, both broadly expressed, which limits therapeutic index. Human cells have roughly 600 E3 ligases, many with restricted expression; some are highly enriched in tumour or lineage-specific tissue. The proposal is to map ligase expression across normal and tumour tissue atlases, prioritise tumour-enriched ligases, and develop handles for them, thereby making degraders tissue-selective.