Q: In this task, you are given a paragraph (from a research paper) and your task is to classify each sentence of the paragraph (assume n sentence) into the following categories: Background, Purpose, Method, Finding/Contribution, or Other. Return the output in this format: 1 - category of sentence 1, 2 - category of sentence 2, ..., n - category of sentence n; where each number indicates the order of the sentence. The categories can be identified using the following questions: 
 Background: - Why is this problem important? - What relevant works have been done before? - What did the previous works miss? - What are the high-level research questions? - How might this help other researchers?
 Purpose: - What specific things do the researchers want to do? - What specific knowledge do the researchers want to know? - What specific hypothesis do the researchers want to test?
 Method: - How did the researchers do it or find it out? - What are the procedures and steps of this research?
 Finding/Contribution: - What did the researchers find out? Did the proposed methods work? - Did things behave as the researchers expected?
Other: put every text fragment that does not fit into any of the categories above here. Put a sentence here if its not in English, is not part of the article, contains numbers and dates, is a caption of a figure or a table, is a formatting error, or you are not sure about it.
We have investigated the role of two polymorphic sites (R190W and N192K) on the binding and activation of the formyl peptide receptor (FPR) by viral and formyl peptides. WEDWVGWI, a peptide with antiviral activity derived from the membrane proximal region of feline immunodeficiency virus, binds with high affinity to FPR. The three tryptophans in the peptide are all essential for FPR binding, just as they were essential for antiviral activity (Giannecchini, S. et al., J. Virol. 77 (2003) 3724). Formyl-NleWEDWVGWI behaved as a weak partial agonist with FPR W190/N192 but a stronger partial agonist with FPR R190/K192 and FPR R190/N192. Formyl-NleNleWEDWVGWI behaved as a full agonist toward all three FPRs but exhibited a much higher EC 50 with W190/N192 FPR (300±45 nM) than for R190/K192 FPR (40±3 nM) or R190/N192 (60 ±8 nM). Formyl-MYKWPWYVWL preferentially activated R190/K192 and R190/N192 FPRs by >5 fold compared to W190/N192 FPR. Formyl-MFEDAVAWF, a peptide derived from a protein in Mycobacterium avium subsp. paratuberculosis and formyl-MFTFEPFPTN, a peptide derived from the N-terminus of chemotaxis inhibitory protein of Staphylococcus aureus with an added N-terminal methionine exhibited the greatest selectivity for R190/K192 and R190/N192 FPRs with ~10 fold lower EC 50S than that observed with FPR W190/N192. Thus, individuals with the W190 polymorphism may display a reduced ability to detect certain formyl peptides.
A:
1 - background, 2 - background, 3 - background, 4 - finding, 5 - finding, 6 - finding, 7 - finding, 8 - finding, 9 - finding, 10 - finding, 11 - finding, 12 - finding