Might (pro-)vitamin A be involved in the relation between palmar keratosis and cancer of bladder and lung?
D000367:Age Factors; D006229:Hand Dermatoses / Q000209:etiology*; D006801:Humans; D007642:Keratosis / Q000209:etiology*; D008175:Lung Neoplasms / Q000150:complications*; D001749:Urinary Bladder Neoplasms / Q000150:complications*; D014802:Vitamin A Deficiency / Q000150:complications*