I Know This Much Is True

Mark Ruffalo

Dominick Birdsey

Mark Ruffalo

Thomas Birdsey

John Procaccino

Ray Birdsey

Rob Huebel

Leo

Gabe Fazio

Shawn Tudesco

Kathryn Hahn

Dessa Constantine

Melissa Leo

Ma

Rosie O'Donnell

Lisa Sheffer

Archie Panjabi

Dr. Patel

Michael Greyeyes

Ralph Drinkwater

Donnie Masihi

Dominick Birdsey - 8 yo

Rocco Masihi

8-Year-Old Thomas Birdsey

Imogen Poots

Joy Hanks

Laura Esterman

Ruth Rood

Marcello Fonte

Domenico Tempesta

Philip Ettinger

17-19-Year-Old Dominick Birdsey

Philip Ettinger

Young Adult Thomas Birdsey

Bruce Greenwood

Dr. Hume

Juliette Lewis

Nedra Frank

Aisling Franciosi

Young Dessa