PTPRH is a receptor-type protein tyrosine phosphatase that functions as a critical regulator of cellular signaling with context-dependent roles in cancer and inflammation. Primary function: PTPRH mediates dephosphorylation of focal adhesion-associated substrates and receptor tyrosine kinases, including EGFR, to negatively regulate integrin and growth factor signaling 1. Mechanism: The phosphatase inhibits PI3K/AKT/mTOR pathway activation and suppresses ERK1/2 phosphorylation 23. Disease relevance: PTPRH expression is frequently dysregulated in cancer through epigenetic modifications. In lung adenocarcinoma, PTPRH hypomethylation correlates with upregulation and poor prognosis 45, while in colorectal cancer, hypermethylation leads to downregulation 6. Conversely, loss-of-function PTPRH mutations in NSCLC result in uncontrolled EGFR phosphorylation, responsive to tyrosine kinase inhibitors 1. Clinical significance: In asthma, PTPRH elevation protects against Th2 inflammation and mucus hypersecretion by suppressing EGFR/ERK1/2/AKT signaling 3. These findings position PTPRH as a potential therapeutic target whose modulation could address both malignant and inflammatory disorders.