Mumbai: Actor Emraan Hashmi, who has penned his struggle around his son Ayan's cancer treatment in a book, says there was a time when he and his wife felt guilty that their son had to battle the disease. At one point, Emraan said he had asked himself, "Where did we go wrong?" Born in February 2010, Ayaan, the first child of Emraan and wife Parveen Shahani, was diagnosed with first stage cancer at the age of four in early 2014. To help raise awareness about the disease and share their story, Emraan has come out with a book titled "The Kiss of Life: How A Superhero and My Son Defeated Cancer" -- which chronicles his career, family, the birth of his son, cancer and treatment thereafter. The book is set to be released in Hindi and Marathi too. "It didn’t anyway, in any way make any sense for us because there was no warning sign, there was no accompanying fever, there was no physical discomfort. There was only one thing that we missed as parents and that was the tumor that had grown on the left side was, there was a bump here and went unnoticed,” Emraan said in a statement. He added: “We thought it (the tumor) was putting on weight and I think the first thing we felt was a feeling of guilt. He was 3 years 10 months then and we’ve made the choices for this kid and where did we go wrong?” There was a phase when they blamed themselves, but after reading up on cancer, he realised they couldn’t blame anyone. “After doing the reading, I realised that. When they removed the tumor, it went through the pathology report and we didn’t know if it was gonna come back because in his case there is the favourable, unfavourable and also there is four stages of cancer,” he said. The actor, known for films like “Murder” and “The Dirty Picture”, spoke about the experience during their child’s cancer treatment phase and how it made him stronger and a better person during an appearance in an episode of the fourth season of “The Tara Sharma” show, hosted by actress Tara Sharma. Emraan has co-written the book with author Bilal Siddiqi. What was the toughest part about the book? The final chapter, said Emraan, who added: “It took me a couple of months to realise to pen that down of how my son in a way kind of inspired me to live my life.” The episode will telecast on Sunday on Star World and Star World HD.