The Dangers of Indels (image) Cold Spring Harbor Laboratory Caption The letters in the human genome carry instructions to make proteins, via a three-letter code. Each trio spells out a word, and the words are strung together in a sentence to build a specific protein. Inserting or deleting a letter ('e' in this example) shifts the three-letter code. Known as a frameshift, these mutations cause the remaining words to be misspelled and the protein sentence to become unintelligible. Credit J. Jansen/ Cold Spring Harbor Laboratory Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.