MAPK1 and lymphoid neoplasm: According to the COSMIC database (http://cancer.sanger.ac.uk/cosmic/gene/analysis?ln=MAPK1, accessed on August 16, 2016), somatic mutations (>74% missense) in MAPK1 have been reported in 89 unique samples, most frequently squamous cell carcinoma and more rarely in melanoma and lymphoid neoplasms, but none in JXG or any other histiocytic disorder.