Vitiligo-like depigmentation and eczematous eruption were noticed two months and four months after starting nivolumab therapy, respectively. After a thorough literature review, we were unable to find Sweet's syndrome secondary to nivolumab, although there are reports secondary to other ICIs, including Ipilimumab (CTLA-4-directed monoclonal antibody), causing Sweet's syndrome [2-4]. The gene discussed is CTLA4; the disease is sweet syndrome.