string: Thus, cannabinoid treatment lowered the expression of the following: (a) VEGF-A [confirming our previous Northern blot data (22)] and its relative VEGF-B (3, 4); (b) hypoxia-inducible factor-1 [one of the subunits of hypoxia-inducible factor-1, the major transcription factor involved in VEGF gene expression (29)]; (c) two genes known to be under the control of VEGF, namely those encoding connective tissue growth factor [a mitogen involved in extracellular matrix production and angiogenesis (30)], and heme oxygenase-1 [an enzyme highly expressed during hypoxia and inflammation (31)]; and (d) four genes known to encode proteins functionally related to VEGF, namely Id3 [a transcription factor inhibitor involved in angiogenesis and tumor progression (32)], midkine [a proangiogenic and tumorigenic growth factor (33)], angiopoi5 See Internet address http://www.