TPPP3 is a microtubule-associated protein that functions as a regulator of microtubule dynamics with robust microtubule bundling activity 1. Unlike its homolog TPPP1, TPPP3 retains comparable microtubule binding and bundling capacity despite lacking an N-terminal tail 1. Mechanistically, TPPP3 organizes cellular microtubule architecture critical for specialized cellular functions. In respiratory cilia, TPPP3 maintains the apical microtubule meshwork necessary for proper basal body positioning and uniform ciliary orientation; TPPP3 deficiency causes random basal body alignment and aberrant ciliary membrane fusions via disrupted sphingolipid homeostasis 2. In olfactory neurons, TPPP3 regulates dendritic microtubule assembly required for basal body migration 2. TPPP3 also marks progenitor cell populations; it identifies early mesenchymal progenitors that contribute to heterotopic bone formation after trauma 3 and paratenon sheath cells involved in tendon regeneration via PI3K-Akt signaling 4. In pathology, TPPP3 dysregulation associates with multiple diseases. Low TPPP3 expression in head and neck squamous carcinoma correlates with poor prognosis and reduced CD8+ T cell infiltration 5. TPPP3 functions as a lactate-related biomarker in nasopharyngeal carcinoma 6. Additionally, Wnt/β-catenin activation in TPPP3+ stromal cells promotes dermal fibrosis through macrophage recruitment 7. In retinal ganglion cells, TPPP3 overexpression promotes axon regeneration and neuroprotection after optic nerve injury 8.