IL6 and breast cancer: Therefore, the presented study aimed to detect a potential association between selected single nucleotide polymorphisms (SNPs)—rs1800797 and rs2069845 in IL-6 and rs2227307 in IL-8—and BC development, as well as to identify the impact of BC on the level of expression and methylation of IL-6 and IL-8 promoters in PBMCs with the use of the TaqMan SNP genotyping assay, TaqMan gene expression assay, and methylation-sensitive high-resolution melting techniques.