SOXC gene inactivation protects mice from TNFα-induced joint degeneration. A, Schematic of the experimental timeline. Dox, doxycycline treatment. B and C, Staining of sections from the distal interphalangeal joint of forepaw digit 3 with Safranin-O/fast green and H&E, respectively. Arrowhead, loss of Safranin-O-stained cartilage-specific proteoglycans. Arrows, invasion the joint cavity by synovial tissue. Asterisk, synovial hyperplasia. D, Fold change in Safranin-O staining intensity in articular cartilage. E, Fold change in the size of the synovium pannus. For both panels E and F, five mice were analyzed per group. Cartilage staining intensities and synovium sizes were measured using ImageJ software in 3 sections/mouse that are 30 μm apart. *, p value in Student’s t-test.