NELL2 and osteochondritis dissecans: Among genes significantly downregulated in the bilateral OD animals, there are many genes not affected or only moderately downregulated in the unilateral OD, EDL, W/Wv, and Nell2−/− animals, endorsing the above observation that a larger number of genes were downregulated in the bilateral OD mice compared with unilateral OD, EDL, W/Wv, and Nell2−/− ones.