Table 1.

Characteristics of RNA viruses.

Virus	Genome	Insert Size	Features	Ref
Retroviruses MMSV MMLV MSCV	ssRNA positive sense	8 kb	Transduction uniquely of dividing cells Packaging cell line Long-term expression Random chromosomal integration	[11,12,13,14,15,16]
Lentiviruses HIV-1 HIV-2 EIAV	ssRNA positive sense	8 kb	Broad host range (non-dividing cells) Long-term, inducible expression Chromosomal integration Low cytotoxicity	[17,18,19,20,21,22]
Alphaviruses SFV, SIN, VEE, M1	ssRNA positive sense	8 kb	Broad host range including neurons Self-amplifying RNA replicon Extreme transient expression Low immunogenicity Lack of efficient packaging system	[23,24,25,26,27,28,29,30]
Flaviviruses KUN, West Nile, YFV, Dengue virus	ssRNA positive sense	6 kb	Relatively broad host range Self-amplifying RNA replicon Transient expression	[31,32,33,34,35,36,37,38,39,40]
Rhabdoviruses Rabies VSV	ssRNA negative sense	6 kb	Relatively broad host range Self-amplifying RNA replicon Low immunogenicity	[41,42,43,44,45,46]
Measles viruses MV-Edm	ssRNA negative sense	6 kb	Self-amplifying RNA replicon Transient expression Oncolytic strains	[47,48]
NDV	ssRNA negative sense	6 kb	Replication in tumor cells Improved oncolytic vectors	[49,50,51,52,53]
Picornaviruses Coxsackievirus	ssRNA positive sense	6 kb	Oncolytic strains	[54,55,56]

HIV, human immunodeficiency virus; KUN, Kunjin virus; MMLV, Moloney murine leukemia virus; MMSV, Moloney murine sarcoma virus; MSCV, murine stem cell virus; NDV, Newcastle disease virus; SFV, Semliki Forest virus; SIN, Sindbis virus; ssRNA, single-stranded RNA; VEE, Venezuelan equine encephalitis virus; VSV, vesicular stomatitis virus; VV, vaccinia virus; YFV, yellow fever virus.