PIK3CA and cervical squamous cell carcinoma: In contrast to clinical results using trastuzumab, another active investigation was conducted in CESC [93], demonstrating that pembrolizumab monotherapy induced complete remission in a recurrent CESC patient with the PIK3CA-E545K mutation, implying that the PIK3CA-E545K mutation could be a potential marker for pembrolizumab treatment in CESC.