close/dear to (someone's) heart

if something is dear to someone's heart, it is very important to them.

Animal rights is an issue very close to my heart.

• in keeping with something
• in kind
• in large part
• in league with
• in league with someone
• in leaps and bounds
• in lieu of
• in light of
• in light of something
• in line for
• in line for something
• in line with
• in line with something
• in living memory
• in loco parentis
• in luck
• in memory of
• in memory of someone
• in midst
• in mind's eye
• in my book
• in my wildest dreams
• in name
• in name only
• in next to no time