请教piggyBac transposons的缺点。xx

dispassion

从原文上看，piggyBac transposons是不整合的可以移除的。可是Junying Yu对它的评价是
8 z) x- h, R+ W% F6 QA second approach used seamless excision of
! F) D! G  Q$ J+ c  V) wpiggyBac transposons to produce vector and transgene-free' z+ Z; o4 r8 s: Q
mouse iPS cells (10). Although a promising approach, vector
- ^( ~5 b/ S& r# F3 rremoval from human iPS cells produced by this method has* A/ A; j) q/ |6 P4 P& Y
not yet been reported, and removing multiple transposons is
' R2 N: e" @' z/ [2 _' m3 klabor intensive.. H# R# ~0 e' q' d" `9 o& R0 t
我想请问她说的缺点是从何而来。谢谢