Sentence:  The US supreme court has ruled unanimously that natural human <WSD>genes</WSD> cannot be patented, a decision that scientists and civil rights campaigners said removed a major barrier to patient care and medical innovation. 
Meaning of the word marked with <WSD> tags:  A theoretical unit of heredity of living organisms ; a gene may take several values and in principle predetermines a precise trait of an organism's form "(phenotype)", such as hair color.