Kathy Griffin shaves entire head in solidarity with sister fighting cancer -- see the pic!

Kathy Griffin wants her sister to know that she's not alone in this fight.

The TV personality has shaved her entire head in solidarity with her sibling's cancer battle, writer Yashir Ali revealed in two pictures shared to Twitter on Monday.

While the pictures were tweeted on Monday, a source tells ET that Griffin actually shaved her head last week.

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After the news, Griffin's mother, Maggie, took to Twitter, writing, "My daughter Kathleen Mary is a wonderful human being."