HOXA4 and breast cancer: An analysis of genome-wide gene expression microarray and DNA methylation microarray explored genes with abnormal DNA methylation in the early detection of breast cancer, among which HOXA4 and IGF1 were identified as increased DNA methylation in breast cancer, which may be used as biomarkers for early detection of breast cancer (Li et al., 2019; Zhuang et al., 2020; Kanathezath et al., 2021).