Extended Data Table 1 |.

Studies of sSNV rates and signatures during ageing in various human cell types^{5–7,76–80}

Study	Tissue/cell	Method	sSNV increase per year per cell	Mutational signatures of aging cells
Blokzijl et al. 20166	adult stem cells of small intestine, colon, liver	WGS of clonal organoid cultures derived from primary multipotent cells	35–40	COSMIC Signature 5
Hoang et al. 201676	bulk brain (frontal cortex), colon, kidney	dilution followed by WGS (BotSeqS)	~33 (in bulk brain)
Lodato et al. 20185	neurons (prefrontal cortex)	single-cell WGS	~23	COSMIC Signature 5
Osorio et al. 20187	hematopoietic stem cells	WGS on clonal cultures	14	COSMIC Signature 5
Franco et al. 201877	skeletal muscle resident progenitor/stem (satellite) cells	WGS on in vitro clonally expanded single cells	13	COSMIC Signatures 1,5,8
Zhang et al. 201978	B lymphocytes	single cell WGS	~26	COSMIC Signatures 1,5
Lee-Six et al. 201979	colon (crypts)	WGS of colorectal crypts, to represent clones from colorectal stem cells	>40	COSMIC SBS5, SBS1
Franco et al. 201980	kidney tubules, epidermis, subcutaneous adipose, visceral adipose	WGS on in vitro clonally expanded single cells	~55 (KT2) ~12 (KT1) ~20 (adipose)	COSMIC SBS1, SBS3/8, SBS5, SBS40
This study	neurons (prefrontal cortex and CA1 hippocampus)	single-cell WGS	16–21	COSMIC SBS5

Of note, COSMIC v3 single base substitution signatures SBS1 and SBS5 are similar and analogous to v2 signatures 1 and 5, respectively (https://cancer.sanger.ac.uk/cosmic/signatures). The table refers to several previous studies.