Table 2.

Comparisons between CAR-T cells and CAR-NK cells.

	CAR-T cells	CAR-NK cells
Sources	mostly autologous T cells; using allogenic T cells may cause GVHD	various sources: PBMCs, UCB, NK cell line, iPSCs, hESCs, HPCs
Transduction efficiency	higher	lower
In-vivo persistence	better	worse
Safety	using allogeneic T cells may cause GVHD;	rarely cause GVHD, may even protect against GVHD;
	CRS and neurotoxicity are two acute side effects observed in CAR-T cell immunotherapy	no CRS and neurotoxicity observed in CAR-NK cell immunotherapy
Efficacy	high: recognize tumor cells through the CAR-dependent manner	higher: recognize tumor cells through both CAR-dependent
		and CAR-independent manners
Convenience	less convenience: necessities of matching HLA;	more convenience: the possibilities to be an off-to-shelf
	the consuming manufacturing time and expensive price	products because of no HLA-restriction and various sources
Current status	two CD19 CAR-T cells have been approved by the FDA;	preclinical and clinical trials have been conducted;
	new types of CAR-T cells have been conducted in clinical trial	several published data are available now