Cal ndi heterodimer, yomwe imapangidwa ndi MRP 8 ndi MRP 14. Imapezeka mu cytoplasm ya neutrophils ndipo imaonekera pa nembanemba ya maselo a mononuclear. Cal ndi mapuloteni a acute phase, imakhala ndi gawo lokhazikika bwino pafupifupi sabata imodzi mu ndowe za anthu, imawonedwa ngati chizindikiro cha matenda otupa m'matumbo. Kitiyi ndi mayeso osavuta, owoneka bwino omwe amazindikira cal mu ndowe za anthu, ali ndi kukhudzidwa kwakukulu kozindikira komanso kutsimikizika kwamphamvu. Mayesowa amachokera ku mfundo ya sandwich reaction ya sandwich ya high specificit double antibodies ndi golide immunochromatographic assay analysis technics, amatha kupereka zotsatira mkati mwa mphindi 15.