 This study found that female mice have different responses to pain than male mice. The estrus cycle plays a role in how much pain females feel, as well as the type of pain they experience. In addition, this study also found that formalinavote pain was accompanied by a male, preferred enrichment in genes associated with the immune modulation of pain. This suggests that there may be a sex-specific immune regulation of pain. This article was authored by Lucy Papino, Pascal Malapert, Andrew Jay Soin, and others.