This review explores the role of hormones in the development and activation of B cells, as well as their impact on autoimmune diseases. B cells play a crucial role in the adaptive immune system by producing antibodies and presenting antigens to T cells. Hormones, such as prolactin (PRL), estrogen, growth hormone (GH), testosterone, and progesterone (P4), influence B cell development, activation, proliferation, and differentiation. These hormones can have both positive and negative effects on B cells, depending on the receptor signal they provide. In autoimmune diseases, hormonal deregulation can promote the survival, activation, and differentiation of autoreactive B cell clones, leading to disease development. Clinical manifestations of autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS), are associated with changes in the levels of these hormones. For example, PRL and estrogen levels are often elevated in SLE patients, while testosterone and P4 levels may be protective. The review highlights the importance of endocrine regulation in modulating the B-cell immune response and discusses the specific roles of each hormone in B cell development and autoimmune diseases.This review explores the role of hormones in the development and activation of B cells, as well as their impact on autoimmune diseases. B cells play a crucial role in the adaptive immune system by producing antibodies and presenting antigens to T cells. Hormones, such as prolactin (PRL), estrogen, growth hormone (GH), testosterone, and progesterone (P4), influence B cell development, activation, proliferation, and differentiation. These hormones can have both positive and negative effects on B cells, depending on the receptor signal they provide. In autoimmune diseases, hormonal deregulation can promote the survival, activation, and differentiation of autoreactive B cell clones, leading to disease development. Clinical manifestations of autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS), are associated with changes in the levels of these hormones. For example, PRL and estrogen levels are often elevated in SLE patients, while testosterone and P4 levels may be protective. The review highlights the importance of endocrine regulation in modulating the B-cell immune response and discusses the specific roles of each hormone in B cell development and autoimmune diseases.