Table 1. Advantage and disadvantage of protein expression systems (modified from Shanmugaraj et al. 2020).

Expression system	Advantage	Disadvantage
Bacteria	Easy to manipulate	Improper folding
	Low cost	Endotoxin accumulation
	High expression
	Existing regulatory approval
Mammalian cells	Proper folding	High production cost
	High yields	Risk of human pathogen contamination
	Existing regulatory approval	Expensive media
Yeast	Rapid growth and scalable	Difficulty in cell disruption
	Easy to manipulate	Limited glycosylation capacity
	Scalable
	Existing regulatory approval
Insect cells	High expression levels	High cost and time consuming
	Proper folding	Expensive media
	Scalable	Nonhuman glycosylation
Plant	Less pathogen and bacterial toxin contamination	Regulatory compliance
	Economical	Limited glycosylation capacity