OAS2 and breast cancer: For example, EPST1 is considered to have immunomodulatory activity and show anti-tumor potential (Zhang X. et al., 2024); OAS2, as a T cell exhaustion-related gene, has been shown to play a role in the regulation of immune responses in breast cancer and non-small cell lung cancer (Lu et al., 2024; Ching et al., 2025).