The phrase "are often in" is frequently used to describe something that is commonly present or occurs frequently. However, there are many synonyms that can be used in place of this phrase to convey the same meaning. For instance, "are frequently found in" or "tend to be prevalent in" can be used. Other alternatives include "are frequently seen in," "are commonly present in," and "are often observed within". Each of these synonyms provide different ways to express the idea of something being regularly present or occurring - allowing for more varied and dynamic language.