IL-1 receptor single knock out mice are not protected from titanium particle-induced osteolysis. Osteolysis was measured in the entire parietal bones (A) and in the suture regions (B). Data are presented as box plots showing the 10th, 25th, 50th, 75th, and 90th, percentiles. In A, n = 16–18 for first and second groups, n = 48 for the third and fifth groups, and n = 34 for the fourth and sixth groups. In B, n = 8–9 for the first and second groups, n = 24 for the third and fifth groups, and n = 17 for the fourth and sixth groups.