TRPA1 and familial episodic pain syndrome: Notably, Trpa1 (Transient Receptor Potential Cation Channel Subfamily A Member 1), a gene that is involved in familial episodic pain syndrome [30] and other forms of nociceptive behavior [31,32,33], was highly upregulated in A/J mice, but only minor changes were induced by SCI in the other strains.