A Nature Communications study by Borremans, Pabba, Zels and colleagues profiled expression of antibody‑drug conjugate (ADC) targets across breast cancer metastases and matched normal tissues, producing a comprehensive map of target distribution. The dataset identifies differential expression patterns that may guide ADC target selection and safety assessments. For developers, the work supplies tumor‑specific and off‑tumor expression data to prioritize payloads and linkers and to anticipate toxicity; the study’s tissue‑level resolution can inform clinical trial design and patient selection strategies. (Clarification: ADCs are targeted therapeutics that link an antibody to a cytotoxic payload to deliver drug selectively to tumor cells.)