This enabled (a) targeting of the most frequent endocrine malignancy, namely, Cldn1‐overexpressing thyroid cancer, and (b) improved targeting of the most common cancer type worldwide, non‐small‐cell lung cancer (NSCLC), which is characterized by high expression of several claudins, including Cldn1 and Cldn5. The gene discussed is CLDN1; the disease is thyroid gland carcinoma.