Cells capable of stem-like behavior

Cell response to injury

Normal stem cell marker

Associated cancer

Cancer marker


Proximal airway (trachea and Bronchi)

Basal cells [10]

Self–renewal and multi-potent abilities [11]

Keratin 5
Transcription factor-63
Trp-63 [12]

Squamous cell carcinoma

Keratin 5 [13]



Midlevel airway (Bronchioles)

Clara cells [14]


Multi-potent but not self-renewal [14]

Secretoglobin, scgb1a1   (CCSP or CC10) [12]





Variant Clara cells [15]


Multi-potent and self-renewal [17]

Lack cytochrome P4502F2 [15]



Small cell lung cancer


Calcitonin gene-related peptide


Pulmonary Neuroendocrine Cells (PNEC) [16]

Self–renewal [17]

Calcitonin gene-related peptide [20]



Distal airway (alveoli)

Bronchoalveolar duct junction cell

Self-renewal [18]

CCSP [19]

Bronchiolar adenocarcinoma


Table 1: Normal lung stem cells and associated lung cancer.