FLT1 and cancer: Radiolabeled VEGF probes targeting the various isoforms, including VEGF-A, VEGF-B, VEGF-C, VEGF-D, VEGFR-1, VEGFR-2, and VEGFR-3, are essential for advancing our understanding of angiogenesis and lymphangiogenesis in both normal physiology and pathological conditions such as cancer [6].