Box plots showing median MCP-1 (solid line) by DENV-1 isolates independent of inoculated virus concentration and days p.i. The line in the middle of each box represents the median; the boxes consists of 1st and 3rd quartile, whiskers are 1.5*(3rd quartile-1st quartile). Outliers are marked with an open circle. The DF-inoculated mice had the highest serum levels of secreted MCP-1 and showed the biggest difference compared to the DSS-inoculated mice (p < 0.0001), followed by DHF-inoculated mice (p = 0.011). MCP-1 levels peaked at day 3 p.i. and whereupon it decreased (p = < 0.001).