ARP also known as MANF is localized in the endoplasmic reticulum (ER) and golgi, and is also secreted. ARP protein plays a crucial role in cellular processes, although specific function remains to be fully elucidated. ARP has been implicated in various malignancies, including primary head and neck, non-small-cell lung, renal cell, breast, and prostate cancers, with mutations in ARP gene being a point of interest in cancer research. While earlier studies suggested that variations in the triplet AGG repeat around codon 50 might contribute to malignancy, more recent investigations have indicated no significant differences in this variation between normal and cancer patient populations.