B2M and Familial prostate cancer: Iron also exhibits relevance to prostate cancer, including FPN level reduction (Chen et al., 2014), redox-sensitive transcription factor (NF-κB) activation (Ornstein and Zacharski, 2007), the HIF1α-dependent pathway activation (Tsui et al., 2013), the association between heme iron intake and prostate cancer risk (Jakszyn et al., 2012), and high level of β2-microglobulin (β2-M) in patients with prostate cancer (Josson et al., 2013).