TERMS COMMONLY USED TO DESCRIBE FORMALIN-FIXED, PARAFFIN-EMBEDDED TISSUES There are terms that you will need to become familiar with when interpreting either your own or other people’s data using either in situ hybridization or immunohistochemistry. These terms are discussed next. ATROPHYAtrophy refers to the thinning of a specific type of tissue. It usually refers to epithelia. Since the epithe..