Col11a1 mRNA is increased by E2 treatment of osteosarcoma cells expressing ERβ, but not ERα, indicating that not only is Col11a1 regulated by E2 but that ERβ is selectively required for its regulation (Gene Expression Omnibus dataset GDS884) [29], although in this case E2 increases rather than decreases Col11a1 expression, as would be predicted by the elevated Col11a1 levels we observe in the absence of ERβ. Here, ESR2 is linked to osteosarcoma.