FOLH1 and neoplasm: Other studies that conduct intraindividual comparisons do exist, but often encounter limitations, such as clinically significant longer intervals between PSMA-PET scans (e.g., Popescu et al. 2024), the comparison of background tissue uptake alone without considering tumoral uptake or tumor-to-background uptake ratios (e.g., Ferreira et al. 2019), or the relatively small number of evaluated patients (e.g. Pattison et al. 2022) [8–10].