JAK1 and cancer: This CD type is divided into two subtypes, type 1 (RCD-1) and type 2 (RCD-2), where the latter features abnormal intraepithelial lymphocytes count and mutations in genes shared by some cancer types, such as Janus kinase 1 (JAK1) or Signal transducer and activator of transcription 3 (STAT3), which play role in the nuclear factor kappa light chain enhancer of activated B cells (NF-κB) pathway, triggering CD-associated lymphomagenesis in CD patients [1,38,39,40,41].