TABLE 2.

Frequencies of SB integration events within intragenic regions of human cells^a

Genomic location	% of integrationsb
	Random	SBc	ASVd	MLVde	HIV-1df	ASLVg
In RefSeq genes	33.2	39.1h	53.0h	50.7h	83.4h	38.2h
5 kb upstream of genes	2.9	3.8	5.1h	13.0h	3.4	ND
±5 kb from transcription start site	5.4	8.5h	8.9h	21.4h	11.4h	ND
±5 kb from CpG islands	8.3	11.2h	ND	ND	ND	ND
±1 kb from CpG islands	1.9	2.5	2.8	15.2h	1.9	3.2

^aCompared with integration frequencies of ASV, MLV, HIV-1, and ASLV. Results from the present study are boldfaced.

^bValues shown for ASV, MLV, HIV-1, and ASLV represent the expected integration frequencies for each vector after the values originally reported were normalized according to the random integration frequencies shown. ND, not determined.

^cSB integrations were compared to 10,000 computer-simulated random integrations and analyzed by using a χ² test for statistical significance.

^dAdjusted values from the work of Narezkina et al. (41).

^eAdjusted values from the work of Wu et al. (58).

^fAdjusted values from the work of Schröder et al. (50).

^gAdjusted values from the work of Mitchell et al. (36).

^hValues are distinguishable from those for random integration (P ≤ 0.03).