In the present study, the relative abundance of Prevotella in rhabdomyosarcoma-bearing APN knockout mice was significantly increased compared to that of rhabdomyosarcoma-bearing wild-type mice, implying an increase of SCFAs from Prevotella to inhibit HDACs may partly attribute to the protection of APN deficiency against rhabdomyosarcoma. This evidence concerns the gene ANPEP and rhabdomyosarcoma.