RPS6KA4 (ribosomal protein S6 kinase A4) is a serine/threonine kinase that functions as a key regulator of gene transcription through histone modification and transcription factor phosphorylation 1. The protein phosphorylates histone H3 at serine-10, resulting in chr11 remodeling and transcriptional activation of immediate early genes 1. RPS6KA4 also phosphorylates transcription factors CREB1 and ATF1 in response to mitogenic and stress stimuli, contributing to gene activation 1. In disease contexts, RPS6KA4 shows significant clinical relevance. Overexpression is associated with poor prognosis in hepatocellular carcinoma, correlating with higher tumor stage, vascular invasion, and reduced overall survival 2. Genetic variants in RPS6KA4 are linked to HBV-related hepatocellular carcinoma survival outcomes 3 and susceptibility to Behçet's disease-related uveitis 4. The gene is also implicated in oral squamous cell carcinoma progression, particularly in perineural invasion cases 5. RPS6KA4 expression is regulated by microRNAs in cystic fibrosis patients with chr11 Pseudomonas infection 6 and is upregulated in regenerative medicine applications involving platelet-rich fibrin and adipose-derived stem cells 7. Additionally, RPS6KA4 is among kinases inhibited by SP600125 in strategies to overcome radiation resistance in tetraploid cancer cells 8.