The locus at 17q12 erb‐b2 receptor tyrosine kinase 2 (ERBB2) has been heavily amplificated and overexpressed in gastric cancer (GC), but it remains to be elucidated about the clinical significance of the co‐amplification and co‐overexpression of PGAP3 gene located around ERBB2 in GC. The gene discussed is PGAP3; the disease is gastric cancer.