Lentivirus vector based on the human immunodeficiency virus-1 (HIV-1) has become a promising vector for gene transfer studies. Lentiviral vectors packaged as lentiviral particles is one of the most efficient tools to deliver exogenous genes into virtually any types of mammalian cells both in vitro and in vivo. The advantageous feature of lentivirus vector is the ability of gene transfer and integration into dividing and non-dividing cells, with low immune response and toxicity in vivo. These viruses also integrate stably into the host genome, enabling long-term transgene expression. Our third generation lentiviral systems have been designed for increased researcher safety. pLenti-SFFV-MCS-PGK-Hygro Lentiviral Expression Vector contains the multiple cloning sites (MCS) driven by SFFV promoter. The multiple restriction enzyme sites are included for convenient cloning of gene of interest. Hygromycin resistant gene driven by PGK promoter is useful for easy detection and selection of transfectants.