Public images are available from these U.S. goverment resources*:
Credit: National Cancer Institute
NCI Visuals Online
Credit: Richard Clark, Darryl Leja, National Human Genome Research Institute, National Institutes of Health
NIH Image Gallery
Credit: Medical Images RM / GARY CONNER, ISM / SOVEREIGN, ISM / Hélène FOURNIÉ, Hero Images
U.S. Government
Medical Images
*Be sure to review and follow respective copyright and licensing requirements.