The combination therapy of somatostatin analog pasireotide and mTOR inhibitor everolimus in the treatment of RAI-RTC was also studied in a phase II clinical trial (NCT01270321), since it was observed that somatostatin receptor (SSTR) 2 was highly expressed in thyroid cancer and activation of the SSTR1-5 inhibited the signal transduction of the PI3K signaling pathway (183). Here, PIK3CA is linked to thyroid cancer.