**Figure 7.** **Association of DNA methylation of TfR1 with clinicopathological parameters of BC patients.** The DNA methylation of TfR1 was investigated in (**A**) BC patients (*n* = 793) and normal individuals (*n* = 97); female (*n* = 783) and male (*n* = 9) BC patients; patients with different BC subtypes (normal individuals, *n* = 97; HER2-positive, *n* = 17; luminal, *n* = 393; and TNBC, *n* = 84); patients with different stages of BC (normal individuals, *n* = 97; stage 1, *n* = 127; stage 2, *n* = 442; stage 3, *n* = 200; and stage 4, *n* = 11); patients with different nodal metastasis statuses (normal individuals, *n* = 97; N0, *n* = 233; N1, *n* = 242; N2, *n* = 95; and N3, *n* = 20); and patients with different ages (normal individuals, *n* = 97; 21–40 years, *n* = 73; 41–60 years, *n* = 374; 61–80 years, *n* = 306; and 81–100 years, *n* = 37). (**B**) Methylation levels of TfR1 in BC through the SurvivalMeth database. (**C**) The heat map of DNA methylation of TfR1 in BC. ^{*}< 0.05, ^{**}< 0.01, ^{***}< 0.001.