Table 1.

CRISPR-tools.

Type	Advantages	Disadvantages	Applied in primary T cells	Ref
Lentiviral	Inclusion of selection marker	Low knock-out efficacy Genomic integration	Yes	[76], [77]
Electroporation	T cells retain expansion potential Extensive protocols are available	Cytotoxic Costly	Yes	[48], [73], [89], [90], [91]
(Lipid) nanoparticles	Highly adaptable to specific need	Complex to engineer	No	[84], [85]
Ligand fusion tags	Cell-type specific	Cells need to express receptor	No	[83]
Cell-penetrating peptides	Produced in-house	Varying quality and efficacy due to batch-to-batch differences	No	[86], [87], [88]