Detection and identification of seminal traces is one of the main forensic tools in cases of sexual assault. In recent years, two semen proteins have been thoroughly investigated: prostate-specific antigen (PSA) and seminal vesicle specific antigen (SVSA), also known as semengelins (Sg) which are the major protein constituents of the semen coagulum. Recently, ectopic expression of Sg was detected in cell lines derived from small cell lung carcinoma (SCLC), from male and female patients, as well as in cell lines from a minority of non-small cell lung carcinoma (NSCLC) tumors. This information prompted this study which investigated the serum of patients affected by lung carcinoma for the presence of Sg. Serum samples from 13 lung cancer patients (3 SCLC and 10 NSCLC) and 10 healthy donors were collected. These samples were screened by enzyme-linked immunosorbent assay (ELISA), using a commercial kit. Four out of 13 serum samples from lung tumor patients showed positive results for Sg. Control samples from healthy donors, negative controls provided in the kit, and mock controls all yielded negative results. The findings appear to confirm a broader distribution of Sg expression than previously thought. Table, references