Which of the following organ is least likely to be involved in Behcet&;s disease

Behcet&;s disease is an inflammatory disorder which affects multiple pas of the body. The most common symptoms include painful mouth sores, genital sores, inflammation of pas of the eye, and ahritisLess commonly there may be inflammation of the brain or spinal cord, thrombosis, aneurysms, or blindnessDiagnosis is based on at least three episodes of mouth sores in a year together with at least two of the following: genital sores, eye inflammation, skin sores, a positive skin prick test (Pathergy test).Ref: Harrison 19th pg: 2194