The star's brother admits recent months have been challenging for the family as Cheng has been in and out of hospital in New Jersey and in his native California, but now he is back at home making slow progress.
Ming Cheng tells rock publication Revolver that his younger brother can now lift his legs but he still can't communicate or move other parts of his body. However, there is still hope.
He says, "Once his health gets a little better, we'll start looking into other options... but they don't even do it (stem cell therapy) in the U.S. yet.
"It's a miracle he's still with us. He's alive and kicking and he's fighting, and I think there's a reason for it. I'm hoping there's a light at the end of the tunnel for Chi."