Novel scavenger receptors having an SR structure and a collectin-like structure are provided, which can be utilized in the elucidation of mechanisms of macrophage and basic immunity; in the elucidation of mechanisms of the development of a wide variety of diseases such as arteriosclerosis, diabetic complications and Alzheimer's disease, hyper .beta.-lipoproteinemia, hypercholesterolemia, hypertriglyceridemia, hypo .alpha.-lipoproteinemia, transplantation, atherectomy, post angiogenic restenosis, bacterial infections; in the diagnostic, prophylactic and therapeutic methods thereof; and in the development of reagents and drugs for the same. The novel scavenger receptors include proteins comprising an amino acid sequence set out in SEQ ID NO: 2, 4 or 24 or proteins having equivalent properties to the same, or derivatives or fragments thereof as well as isolated polynucleotides comprising a nucleotide sequence encoding these proteins, and related molecules such as antibodies, antagonists and the like. Also disclosed are methods for the treatment using the same.