Immunotherapy, which stimulates the body’s immune system, has received a considerable amount of press in recent years because of its powerful benefits. Cancer immunotherapy has shown long-term results in patients with advanced disease that are not seen with traditional chemotherapy. Immune checkpoint inhibitors, cytokines like interleukin 2 (IL-2) and interferon-alpha (IFN), and the cancer vaccine sipuleucel-T have all been licensed and approved by the FDA for the treatment of various cancers. These immunotherapy treatments boost anticancer responses by stimulating the immune system. As a result, they have the potential to cause serious, even fatal, inflammatory and immune-related side effects in one or more organs. Immune checkpoint inhibitors (ICPIs) and chimeric antigen receptor (CAR) T-cell therapy are two immunotherapy treatments that are increasingly being used to treat cancer. Following their widespread usage in the clinic, a wave of immune-related adverse events (irAEs) impacting virtually every system has raised concerns about their unpredictability and randomness. Despite the fact that the majority of adverse effects are minimal and should be addressed with prudence, the risk of life-threatening complications exists. Although most adverse events are small and should be treated with caution, the risk of life-threatening toxicities should not be underestimated, especially given the subtle and unusual indications that make early detection even more difficult. Treatment for these issues is difficult and necessitates a multidisciplinary approach involving not only oncologists but also other internal medicine doctors to guarantee quick diagnosis and treatment. This study’s purpose is to give a fundamental overview of immunotherapy and cancer-related side effect management strategies.

Neurological disorders involve complex interactions between neurotransmitters and immune signaling pathways, with serotonin (5-HT) and interleukins (ILs) playing crucial roles. This review explores the mixed pathway of 5-HT-IL signaling and its involvement in the pathophysiology of neurodegenerative and neuropsychiatric conditions. Dysregulated 5-HT and IL signaling has been implicated in Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, depression, anxiety, schizophrenia, autism spectrum disorder, and attention-deficit/hyperactivity disorder. 5-HT influences neuroinflammation, synaptic plasticity, and cognitive function, while ILs regulate immune responses and neuronal survival. Their interplay modulates neurotransmission, neuroinflammation, and neurodegeneration through mechanisms, such as cytokine-mediated 5-HT depletion and 5-HT receptor regulation. Understanding the 5-HT-IL pathway offers new insights into disease progression and potential therapeutic strategies, including selective 5-HT reuptake inhibitors, cytokine inhibitors, and combination therapies targeting neuroimmune interactions.