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The human body produces and destroys 15 million blood cells every second.
The strongest synthetic topical retinoid drug available, tazarotene, is used to treat sun-damaged skin, acne, and psoriasis.
There are over 65,000 known species of protozoa. About 10,000 species are parasitic.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.
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