unusual variant
unwanted consequences
unwanted effects
unwanted hair

unwanted pregnancy
unwanted side-effects
unwanted side effects
unwarranted assumptions
unweighted pair-group method

unweighted pair group method
up-and-down method
up-regulated expression
up-regulated genes
up-regulated proteins

up-regulation
up-to-date
up-to-date information
up-to-date knowledge
up-to-date overview