Answer:
The italic is, along with the capital letters and quotation marks, one of the three basic procedures to indicate that a word or group of words has a special meaning that does not correspond to that of the common lexicon of the language. These three procedures are rarely combined (except in the proper and capitalized names of the first word of an expression, title, quotation or similar).
The main functions of the italics are of emphasis and to point out to the reader that a phrase or a common word may be alien to him as a neologism, being part of a jargon or slang, adopting an incorrect form or functioning as a metalanguage, that is, no Be part of the speech with the proper meaning of the words.