Expression of isoforms of the CD44 is generated by alternative splicing of CD44 gene; CD44H: lacks all 10 alternative exons, CD44R: the alternative exons v8 to v10, CD44V: other group of variants which contains the alternative exon v6. In some tumors such as colorectal cancer, breast cancer, non-Hodgkin lymphoma, and melanoma, over-expressed CD44 isoform which contains such alternative-spliced variant exons may play a causative role in tumor metastasis. In lung cancer, however, the role of CD44 variants in tumor progression and metastasis is uncertain. In our study and reported literature, no definite correlation was observed between the expression of specific CD44 isoform and tumor progression or metastasis of lung cancer.