In living organisms, protein molecules with different chemical structures called proteoforms, are produced from a single gene to perform a variety of physiological protein functions. It has been known for quite some time that humans have approximately 22,000 genes, but the total number of human proteoforms is still unknown. In living organisms, protein molecules with different chemical structures called proteoforms, are produced from a single gene to perform a variety of physiological protein functions. It has been known for quite some time that humans have approximately 22,000 genes, but the total number of human proteoforms is still unknown. Biochemistry Analytical Chemistry Phys.org – latest science and technology news stories