FX binding to murine SR-AI–deficient macrophages. (A-C) CD115⁺-derived macrophages from wt (A) or SR-AI–deficient (B) C57BL/6 mice incubated with human FX (10 µg/mL, 1 hour at 37°C) were double immunostained for murine SR-AI (red) and human FX (green). Images were acquired in widefield microscopy and subsequently quantified for FX fluorescence (C). Data are presented in mean pixel intensity per cell. Boxes represent the median and 25th to 75th percentile, and bars represent the 10th to 90th percentile (at least 5 different fields per experiment in 3 different experiments). Nuclei and polymerized actin were counterstained using DAPI (blue) and Alexa 647–labeled phalloidin (magenta), respectively (A and B). Objective, ×63; bars represent 10 µm; ***P < .001, respectively, in the Mann-Whitney nonparametric unpaired statistical test.