Table 1.

Possible systems involved in SARS-CoV-2, SARS-CoV and MERS-CoV infections.

Involved system	SARS-CoV-2	SARS-CoV	MERS-CoV
Cell surface receptor2,3	Human ACE2	Human ACE2	Human DPP4
Mortality rate2	Lowest	Middle	Highest
Immune system	+4‡	+2†,5†	+2†,5†
	Alveolar macrophage cells4‡	Tissue-resident macrophages2†,5†	Tissue-resident macrophages (lung, skeletal muscle)2†
			Monocytes5†
			T lymphocytes5†
			Histiocytic cell lines5†
Respiratory system	+4‡,6‡,7‡	+2†,5†	+2†,3†,5†
	Alveolar epithelial cells5‡	Respiratory alveolar epithelial cells2†,5†	Pneumocytes3† Multinucleated epithelial cells
			Bronchial submucosal gland cells2†,3†,5†
Neurological system	+6‡	+3†	+5†
		Neurons in the brain3†	Neurons in the brain5†
Digestive system	–4‡; +6‡,7‡,8†	+3†,5†	+3†,5†
	Liver7‡	Intestinal mucosa3†	Intestinal mucosa3†
		Liver epithelium6†	Liver epithelium5†
Genitourinary system	–4‡; +6‡	+2†,5†	+2†,5†
		Renal distal tubule epithelium2†	Renal proximal tubular epithelial cells2†
		Kidney5†	Kidney and prostate5†
Cardiovascular system	–4‡,6‡,7‡	+10a	+10a

Note: Evidence of COVID-19 is presented with autopsy data due to the lack of a recent cell line study.

+: affected according to cell line susceptibility data (in vitro) ^† or pathological findings on autopsy ^‡

–: not affected according to pathological findings on autopsy.

^aNo current cell line susceptibility or autopsy data available (only anecdotal evidence).