A former Chinese e-commerce executive in the final stages of a rare disease is still working 12-hour days, devoting what time he has left to accelerating the search for a cure.Cai Lei, 48, a former vice-president of JD.com, one of China’s largest e-commerce companies, has spent seven years battling amyotrophic lateral sclerosis (ALS), an incurable disease that progressively attacks motor neurons.His condition has recently deteriorated to an advanced stage. Unable to move or speak, Cai can now...