The RSK (Ribosomal S6 Kinase) family is part of the serum/glucose kinase group, consisting of at least four homologous proteins: RSK1, RSK2, RSK3, and RSK4. These kinases possess two functional kinase domains located at the N-terminus and C-terminus, which can be phosphorylated and activated by ERK1/2 (Extracellular Signal-regulated Kinase). RSK is localized in both the nucleus and cytoplasm, regulating various biological processes including cell growth, division, survival, and differentiation. RSK exerts its effects by phosphorylating downstream substrates such as transcription factors and other proteins. Aberrant expression and activity of RSK family members are associated with various diseases, such as cancer, neurodevelopmental disorders, and skeletal abnormalities. Precise regulation of the RSK pathway is essential for cellular function and disease therapy.