S100P and breast cancer: Patients with larger BC tumors had lower methylation levels in S100P_CpG_4, S100P_CpG_8, and S100P_CpG_9 (p < 0.05; Supplementary Table 6), and patients with positive human epidermal growth factor receptor 2 (HER2) receptors showed lower methylation levels in S100P_CpG_4 and S100P_CpG_10,11,12 (p < 0.05; Supplementary Table 6).