IMPLICATIONSFOR PATIENT CARE: As a direct transcriptional target of hypoxia-inducible factor 1α, CAIX is overexpressed in ccRCC and hypoxic tumors, such as CRC and PDAC; the theranostic pair [68Ga]Ga-DPI-4452 and [177Lu]Lu-DPI-4452 provides a novel selection strategy and treatment modality for targeting CAIX-expressing tumors. The gene discussed is CA9; the disease is colorectal carcinoma.