Cal bụ heterodimer, nke mejupụtara MRP 8 na MRP 14. Ọ dị na cytoplasm neutrophils ma gosipụta ya na membranes cell mononuclear. Cal bụ protein na-agba agba, ọ nwere usoro kwụsiri ike nke ọma ihe dị ka otu izu n'ime afọ mmadụ, e kpebisiri ike na ọ ga-abụ akara nrịanrịa na-afụ ụfụ. Ngwa ahụ bụ ule dị mfe, nke na-ahụ maka ọkara nke na-achọpụta cal n'ime afọ mmadụ, ọ nwere mmetụta nchọpụta dị elu yana nkọwa siri ike. Nnwale ahụ dabere na ụkpụrụ mmeghachi omume Sanwichi okpukpu abụọ dị elu yana teknụzụ nyocha nyocha nke immunochromatographic ọla edo, ọ nwere ike inye nsonaazụ n'ime nkeji iri na ise.