Lck inhibitors are primarily used in the field of medical research and therapeutics, particularly in the treatment of autoimmune diseases and certain types of cancers. By targeting the Lck (lymphocyte-specific protein tyrosine kinase) enzyme, these inhibitors help modulate T-cell activation, which is crucial in immune response regulation. In autoimmune conditions like rheumatoid arthritis and multiple sclerosis, Lck inhibitors can suppress the overactive immune system, reducing inflammation and tissue damage. Additionally, they are being explored in oncology to hinder the proliferation of T-cell lymphomas and leukemias, where Lck activity is often dysregulated. Their potential in immunotherapy, especially in combination with other treatments, is a significant area of ongoing research.