a
|
time−2
|
Spontaneous stem cell initiation and transformation |
b
|
time−1
|
Pre-malignant niche replication |
c
|
time−2
|
Age-dependent pre-malignant cell senescence |
δ
|
time−1
|
Homeostatic regulation of pre-malignant cell number per niche |
Z
|
cells/niche |
Carrying capacity for pre-malignant cells per niche |
X
|
time/dose |
Radiation-induced initiation |
Y
|
dose−1
|
Radiation-induced promotion |
α, β |
dose−1, dose−2
|
Stem cell inactivation by radiation |
λ |
time−1
|
Maximum net stem cell proliferation (repopulation) rate |
L
|
time |
Lag period between the first malignant cell and cancer |