Furthermore, mTOR expression was not affected by pimozide, likely as other signals are involved in the regulation of mTOR, such as the p53 pathway.48 Since previous studies showed that RAF1 can form a complex with phosphodiesterase, which hydrolyzes cAMP, while cAMP can down-regulate RAF1 expression depending on the PKA pathway and cAMP can promote autophagy,36,37,49 we tested the expression of cAMP by FRET and found that pimozide treatment increased the expression of cAMP in breast cancer cells, which may lead to enhanced autophagy in breast cancer cells. Here, MTOR is linked to breast cancer.