Chi-conotoxins inhibit the neuronal noradrenaline transporter (NET/SLC6A2). Expressed by the venom duct. The cysteine framework is X (CC-CX[hydroxyPro]C). Is under phase II clinical trial by Xenome under the name Xen2174. This structural analog of MrIA was developed to overcome the relatively poor chemical stability of Mr1A in solution. Used to treat neuropathic pain. Exists in two forms, due to cis-trans isomerization at 59-His-Hyp-60. This toxin does not produce effects on the activity of the dopamine transporter (DAT/SLC6A3) and the serotonin transporter (SERT/SLC6A4). Belongs to the conotoxin T superfamily.