We found that SIGLEC15 was negatively related to BRCA1 in the mRNA level but no correlation with BRCA2. We also found that high SIGLEC15 had a negative correlation with DDR deficiency scores, such as aneuploidy score, CNA frac altered, and LOH frac altered, and these results implied that SIGLEC15 may affect thyroid cancer progression through interacting with DDR genes. The gene discussed is BRCA2; the disease is thyroid cancer.