Bollywood actor Emraan Hashmi has thanked megastar Amitabh Bachchan for his inspiring note to his son, Ayaan and called him the 'original superhero'.

Hashmi recently released a book on his son's battle with cancer, titled 'Kiss of Life', which talks about the hardships he and his wife faced when their son was diagnosed with cancer at the age of four in 2014. Bachchan had sent a special letter for the 37-year-old actor's son, which Hashmi shared on Twitter.

"Thanks @SrBachchan for the note. Ayaan aspires to be Batman. And Batman aspires to be you. You are the original superhero!" he wrote.

Bachchan replied saying, "Really what a remarkable son .. god bless him and may he remain healthy ever..."