Andrew Strauss, the director of England cricket, has announced he is to take an extended break from the game to spend time with his family.
Strauss' wife, Ruth, was diagnosed with cancer a few months ago and it is understood the condition has worsened. The couple have two young sons.
Andy Flower, the former England coach and current Lions coach, will take over Strauss's duties in an interim capacity. No time frame has been given for his return.
"My wife was diagnosed with cancer in December," Strauss said on Tuesday. "We are very lucky, she has been very well up to now, although she is starting a new treatment on Friday which is going to more challenging for her, and as such I am going to be stepping back from my day-to-day duties while that treatment is going on.
"On a day-to-day basis Andy Flower is going to be stepping in for me over the course of the summer. We all know about his qualities and his experience of both England and English cricket and he will fill in my shoes very adequately.
"I look forward to returning and grabbing the reins again. But, at this period of time, my focus has to be on supporting Ruth and my family at a challenging time for us."
Strauss flew home from this winter's Ashes tour after the initial diagnosis in December and did not rejoin the team in Australia, although he did return to work in the new year.
Last month, Strauss unveiled Ed Smith as England's new national selector, replacing James Whitaker who stood down in March. He was also involved in the ECB's unveiling of their proposed new 100-ball tournament, as well as the working party looking into the future structure of county cricket.
Strauss met his wife, an Australian actress, while playing grade cricket in Sydney in 1998-99. The pair married in 2003.
In 2009, when Strauss led England to victory in that summer's Ashes, Ruth was credited by her husband for her role in keeping him grounded when the pressure of the series was at its highest, particularly during Australia's series-levelling victory in the fourth Test at Headingley.