GSTM1 and hemoglobin measurement: HB gene mutations are simple, and whole-exon sequencing shows that there are only 2.9 mutations per HB tumor on average [13], which is much lower than 35–66 mutations per tumor in liver cancer [14–16], indicating that HBs are not only caused by the accumulation of gene mutations; in addition, most HBs occur in children, suggesting that epigenetic mechanisms that control development play an important role in the occurrence and development of HB.