ACP3 (acid phosphatase 3) is a prostatic acid phosphatase expressed specifically in prostate epithelial and cancer cells 1. The enzyme exhibits acid phosphatase activity and is structurally homologous to lysosomal acid phosphatase, sharing 50% sequence homology 2. In the context of microbial infection, ACP3 forms amyloid β-sheet fibrils in semen known as SEVI (semen-derived enhancer of viral infection), which capture and enhance HIV infection by facilitating virion attachment to target cells 34. These SEVI fibrils can be degraded by green tea polyphenols and inhibited by surfen compounds 45. Clinically, ACP3 has emerged as a highly specific target for prostate cancer therapy. PAP-targeted CAR-T cells demonstrate potent antitumor efficacy in prostate cancer models 1, and high-affinity ligands like OncoACP3 show picomolar binding affinity with selective tumor accumulation and long tissue residence times 6. [68Ga]Ga-OncoACP3-DOTA PET imaging demonstrates low off-target uptake in salivary glands and kidneys compared to PSMA-targeted agents, providing superior biodistribution profiles for imaging and radioligand therapy 7. These characteristics make ACP3 a favorable alternative target to PSMA for prostate cancer diagnosis and treatment.