Endochondral bone formation in HLA-B27 transduced ATDC5 micromasses. Endochondral bone formation in HLA-B27 transduced ATDC5 micromasses. (A) Expression of Acan, Col2 and Col10 measured by quantitative RT-PCR in the HLA-B27 and HLA-B7 ATDC5 micromasses. Statistical analysis was performed by two-way ANOVA. p<0.05 was considered as statistically significant. Data points are shown as average and SEM (n=3). (B) Alcian blue and Alizarin red staining at the different time points. Acan, Aggrecan; Col2, Collagen type II; Col10, Collagen type X. Barbara Neerinckx et al. RMD Open 2017;3:e000451 Copyright © BMJ Publishing Group & EULAR. All rights reserved.