Duoyi Zhao

1 Introduction Within the gastrointestinal tract, there exist over a billion varieties of microbiota to ensure the normal functioning of the digestive system, encompassing known and unknown bacteria, fungi, protists, and viruses, collectively shaping a dynamic equilibrium within the gut, known as the microbiome.[1] This equilibrium demonstrates relative stability and a certain resilience.[2] Primarily dominated by bacteria, the indigenous flora in the adult gut comprises four major phyla:...

1 Introduction Malignant bone and soft tissue tumors (BSTT), known as sarcomas, represent rare non-epithelial malignancies originating in bone and various bodily tissues, including muscles, fat, blood vessels, nerves, and connective tissues. These malignancies encompass several subtypes, including osteosarcoma, chondrosarcoma, Ewing’s sarcoma, leiomyosarcoma, liposarcoma, rhabdomyosarcoma, and synovial sarcoma.

1 Introduction Osteosarcoma (OS) is the most common malignancy in children and adolescents, accounting for 0.2 percent of all malignancies (Rossi and Del Fattore, 2023). In the US, approximately 4.4 patients per million children and adolescents have OS (Longhi et al., 2006). OS originates from mesenchymal stem cells and occurs in the long diaphyseal epiphysis in children and adolescents, more commonly in the distal femur, proximal tibia, and humerus (Brown et al., 2018; Dong et al., 2022).