Table 1.

Abbreviations, parameters, units, and values.

TL20	TL at age 20 years (kb)
TLX	TL at x years older than 20 years (kb)
TLB	Telomeric brink, stopping cell replication (5 kb)
TLO	TL at onset of clone size limitation (6.4 kb)
XO	Age in years when TL0 is reached
CS	Clone Size
MCS	Maximal Clone Size (∼ 106 T cells)
LCS	Limited Clone Size (< MCS)
Δmax	TL shortening required for achieving MCS (∼ 1.4 kb)
g	TL shortening rate with age (∼ 0.03 kb/year)
r	TL shortening rate per T-cell replication (∼ 0.07 kb)
N	Number of T-cell replications in LCS (after TLO, XO)
Nmax	Number of T-cell replications in MCS (before TLO, XO)