HDAC9 and breast carcinoma: There is also some evidence pointing to hypoxia downregulating LIFRβ, as hypoxic conditions decreased LIFRβ expression in breast cancer cells and multiple hypoxic responsive elements have been identified in the LIFRβ promotor (62).That same group also identified histone deacetylase (HDAC) as a potential mechanism for LIFRβ downregulation, which is supported by evidence indicating that LIFRβ is upregulated when breast cancer cells were treated with HDAC inhibitors (28) (62).