MAPK11 (p38β) is a serine/threonine kinase that functions as an essential component of the p38 MAPK stress-activated signaling cascade 1. As one of four p38 MAPK isoforms, MAPK11 plays important roles in cellular responses to extracellular stimuli including pro-inflammatory cytokines and physical stress, leading to activation of transcription factors 1. The kinase phosphorylates a broad range of substrates and exhibits largely redundant functions with MAPK14 (p38α) 1. MAPK11 promotes phosphorylation of key downstream targets including RBBP6 at Ser772, which leads to SIRT6 protein degradation in cancer-associated fibroblasts 1. In hepatocellular carcinoma, MAPK11 expression is transcriptionally activated by ETV4, contributing to TNF-α signaling and hepatic inflammation 2. The kinase also regulates extracellular matrix internalization and cancer cell migration through α2β1 integrin-mediated pathways 3. Additionally, MAPK11 promotes MAPK11-PML phosphorylation, which can be modulated by anesthetic agents like Ciprofol to reduce glioma recurrence 4. Expression analysis reveals that MAPK11 is generally downregulated in several female cancers including breast, endometrial, and ovarian cancers compared to normal tissue 5, while being upregulated in certain inflammatory conditions like idiopathic multicentric Castleman disease 6.