Cuiying Ye

1 Introduction Acute respiratory tract infections (ARTIs) continue to pose a significant public health challenge worldwide, particularly in children, due to their immature immune systems and underdeveloped respiratory mucosal barriers [1, 2]. As one of the most common illnesses in children, especially infants and young children under 5 years of age, ARTIs not only result in substantial consumption of healthcare resources but also present long-term risks to children's growth and development [3].

Abstract Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy, and despite advances in therapy, relapse remains a major cause of treatment failure. Liquid biopsy has emerged as a powerful, minimally invasive tool for real-time disease monitoring and prognostication in hematologic malignancies.

1 Introduction Epstein–Barr virus (EBV) is a relatively common double-stranded DNA virus belonging to the gamma subfamily of herpesviruses. It can be transmitted through saliva (commonly known as the “kissing disease”), blood transfusion, organ transplantation, and other routes, and is associated with a variety of clinical diseases (1). EBV exhibits widespread susceptibility in the general population.