M-APTA (5'-S- (3-aminophenyl) -5'-thioadenosine) is a selective chemoprotective agent targeting methylthioadenosine phosphorylase (MTAP) . m-APTA can be converted into adenine, which is a crucial step in protecting normal cells from the toxicity of nucleobase analogues (NBA) . m-APTA is promising for research of MTAP-deficient cancers[1].