Specifically, mutations in CSMD1 resulted in infertility problem both in males and females through ﻿complement-related processes [18]; the loss of CSMD1 could be found in head and neck squamous cell carcinoma (HNSCCs), lung squamous cell carcinoma (SCCs), melanoma, and breast cancer [9–11]; downregulation of CSMD1 mRNA expression by methylation of the CpG island in its promotor region was critical in the progression of hepatocellular carcinoma [19]. This evidence concerns the gene CSMD1 and breast cancer.