HBO has unveiled its a new, rather weighty trailer for “I Know This Much Is True,” its upcoming limited series starring Mark Ruffalo as identical twins. Related News. HBO has shifted the premiere date of the Mark Ruffalo-led limited series “I Know This Much Is True.” The six-episode series will now debut May 10. The project hails from Mark Ruffalo, who stars in a du… HBO has delayed the release of the forthcoming Mark Ruffalo drama I Know This Much Is True by two weeks. Deadline understands … Share New casting has been announced for I Know This Much Is True … HBO’s I Know This Much Is True Starring Mark Ruffalo Delayed Until May. It was originally set to begin airing … The limited series comes from director … Mark Ruffalo Shines as Twins in HBO’s ‘I Know This Much Is True’ Trailer 20 March 2020 | Collider.com; I Know This Much Is True Trailer Has Mark Ruffalo Playing Twins on HBO HBO has greenlighted for production I Know This Much Is True, a six-episode limited drama series based on Wally Lamb’s bestselling book. Mark Ruffalo’s drama I Know This Much Is True has got a new premiere date after HBO pushed the limited series by two weeks.. Mark Ruffalo will star and executive-produce the upcoming limited series based on the Wally Lamb novel.