Furthermore, typical neuroendocrine (i.e., smaller cells with, e.g., L-MYC+, ‘neural cell adhesion molecule’ [NCAM or CD56]+, Synaptophysin+) and atypical mesenchymal (i.e., larger cells with, e.g., Vimentin+, Nestin+, ‘homing cell adhesion molecule’ [HCAM or CD44]+) expression patterns were found after extraction of SCLC tissue from mice. The gene discussed is CD44; the disease is small cell lung carcinoma.