The alteration frequency of PIK3CA and PTEN varies significantly in different populations: for example, between Asian and Caucasian GC patients, the rate is 7% compared to 15% for PIK3CA mutations, 21% compared to 4% for PTEN deletion, and 47% compared to 78% for PTEN loss, respectively [134]. The gene discussed is PTEN; the disease is gastric cancer.