Transcriptional repressor NF-X1 (NFX1)

Binds to the X-box theme of MHC class II genes and represses their expression. May play an essential role in regulating the duration of an inflammatory response by limiting the period in which MHC class II molecules are triggered by interferon-gamma.

Isoform 3 binds to the X-box theme of TERT promoter and represses its expression. Together with PABPC1 or PABPC4, isoform 1 acts as a coactivator for TERT expression.