FOLH1 and neoplasm: The authors found that changes in dye composition impacted the photophysical properties, stability in serum (range 76% ± 0–89% ± 6%), plasma protein interactions (range 85.0% ± 2.3–90.7% ± 1.3%), PSMA affinity (IC50 range 19.2 ± 5.8–175.3 ± 61.1 nM) and in vivo features (tumor-to-prostate and tumor-to-muscle ratios range 0.02 ± 0.00–154.73 ± 28.48 and 0.46 ± 0.28–5157.50 ± 949.17, respectively; renal, splenic, and salivary retention).