Anti-PRH2 antibodies are used in the immunodetection of the protein proline rich protein HaeIII subfamily 2. Synonyms for this target antigen include Pr, pr1/Pr2, salivary acidic proline-rich phosphoprotein 1/2, acidic salivary proline-rich protein, HaeIII type, 2, and PRP-1/PRP-2.