UNC80 and alcohol drinking: In addition, two previous studies suggest the existence of a susceptibility locus located on chromosome 2, near the UNC-80 gene, linked to alcohol tolerance (markers D2S425, D2S434, D2S424, D2S1323, D2S1333) and the comorbidy of alcoholism and depression (marker DS1371) respectively (Nurnberger et al., 2001; Schuckit et al., 2001).