Additionally, ROS promotes the expression of USP7, which promotes the expression of P53, and ROS also promotes the expression of BRD4.Based on the results of Western blot, flow cytometry, CCK-8 assay, clone formation assay, and subcutaneous xenograft tumor experiment in nude mice, we can conclude that 125I particle radiotherapy enhances the expression of ROS, USP7, and P53 by promoting the HSF1/PU.1/SYK signaling pathway, thereby promoting the apoptosis of C33A cells and inhibiting their proliferation. The gene discussed is SPI1; the disease is neoplasm.