A functional 287‐nucleotide fragment insertion/deletion (I/D) polymorphism in intron 16 of the ACE gene accounts for approximately 50% of ACE levels (Rigat et al., 1990), is the most studied RAS‐related polymorphic variant, and is the only RAS‐related polymorphism investigated in the etiology of nicotine dependence so far (Baghai et al., 2008; Hubacek et al., 2001, 2004). The gene discussed is ACE; the disease is nicotine dependence.