Mississippi author Greg Iles has told his friends and readers he has blood cancer and will soon undergo a stem cell transplant.

The New York Times best-selling author, who lives in Natchez, Miss., is set to release his next novel “Southern Man,” in May. The book will be the latest installment in his popular Penn Cage series.

“In 1996, when I was 36 years old, I was diagnosed with multiple myeloma, an incurable blood cancer that had recently killed Sam Walton, the founder of Walmart,” Iles wrote in a letter released on Monday on his website, gregiles.com.

Iles wrote that he was asymptomatic at the time of his diagnosis, even though he carried most of the signs of full-blown disease, giving him a “very brief survival prognosis.

“After nearly dying from an experimental treatment, I — with the blessing of my father, the inspiration for Dr. Tom Cage — withdrew from the medical system and continued my writing career, while keeping my illness completely secret,” he wrote.

He survived 20 years without the disease progressing.

However, two years ago, his “extraordinary run of luck ran out, and my myeloma ‘switched on.’ I nearly died before I was even aware that the disease had reawakened.”

He said he was in the process of writing “Southern Man” when he became ill and decided to complete that novel before pursuing treatment in the form of a stem cell transplant.

“This should explain the multiple postponements of the release that generated so many emails and which I was unable to answer candidly at the time,” Iles wrote.

He said he would be undergoing his stem cell transplant before publication of the book.

Iles said he and his publisher would keep readers apprised of his progress during his recovery.

“Please be assured I am receiving excellent treatment, and at this time, I won’t be able to answer large numbers of emails, but I’ll do my best to read them as I focus on my recovery. One thing this experience has taught me is that there is nothing unique about my situation. Many, many people are struggling with similar ailments, and I wish for them all the best possible outcomes.

“This journey is far from over. My last thought for today is that only two things matter: family and friends,” Iles wrote.