Moreover, high HHLA2 levels in the patients with PTC significantly correlated with more advanced AJCC and TNM stages and with more prominent lymph node metastasis, while HHLA2 expression was not significantly associated with other clinical features such as gender, age, tumor size, multifocality, depth of invasion, or extrathyroidal invasion. The gene discussed is HHLA2; the disease is neoplasm.