When we want to express that two things are different or not similar, we often use the phrase "are unlike." However, there are many synonyms that can be used in place of this phrase to add variety and nuance to your writing. Some options include "differ," "vary," "contrast," "diverge," "deviate," "disparate," "unrelated," "distinct," "unique," and "incompatible." Each of these words carries its own connotations and can help you more accurately convey the nature of the difference between two things. Experimenting with different synonyms can make your writing more interesting and engaging.