Jennifer Aniston and Courteney Cox in 2015

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Jennifer Aniston took a nostalgic trip down memory lane as she celebrated Courteney Cox on her pal and former co-star's birthday.

Posting a string of throwback photos of herself and Courteney on Instagram, the former Friends star wrote: "I'd like to take a moment and wish my dearest CC the happiest of birthdays. If you've been lucky enough to know her, you know how incredible she is.

"The biggest heart and most generous of humans.

Sharing her silly nickname for the Monica Geller actor, Jen concluded: "I love you, Cox-N-Hammer! Happy Birthday."

Courteney then revealed she had a nickname of her own for the Morning Show star, writing back: "I love you Jenny Louise."

Earlier this year, Jen paid tribute to Courteney at the unveiling of her star on the Hollywood Walk Of Fame.

"To be friends with Courtney is to be family with Courtney, and she is responsible for all of that," Jennifer said in her unveiling speech.

"From the beginning of when we met her, she was immediately inclusive, warm, loving, interested in everything about you.

Courteney Cox, Lisa Kudrow and Jennifer Aniston share a hug

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Jen later added of their early years working together on Friends: "From the beginning, she made it very clear that this was a true ensemble. She instilled into all of us to support each other and to love one another and that actors need to support and love one another."

In an interview from around this time, she also shared one of her favourite memories from working with Courteney on the Emmy-winning sitcom.