The direction of change was more commonly observed from PIK3CA mutated to wild-type status (14.9%, 95% CI 11.8–18.2; n studies = 24, n tumor pairs = 453; I2 = 35.3%) (Fig. 2B) rather than from PIK3CA wild-type to mutated status (8.9%, 95% CI 6.1–12.1; n studies = 24; n tumor pairs = 943; I2 = 56.4%) (Fig. 2C). Here, PIK3CA is linked to neoplasm.