Serologies for Herpes Simplex Virus (HSV) IgM and Cytomegalovirus (CMV) IgM were also negative. Biopsy was reported as non-specific colitis with mucosal haemorrhage, and there was no evidence of vasculitis. Based on these findings, she was diagnosed with haemorrhagic enterocolitis secondary to CPA therapy (Common Terminology Criteria for Adverse Events (CTCAE) version 5.0, Grade 4). This evidence concerns the gene CD40LG and colitis.