"That's... what Sasori's medicine did... why it was considered poison..." he repeated, more of a confirming statement than a question. "It suppressed the immune system..."

That, in itself, was a frightening thought. A simple infection really could be enough to kill him.

He took a few more breaths, and realized that it didn't hurt as much as it usually did. Kabuto really had healed a fair amount of the damage, drained the blood. Of course, Itachi knew it couldn't have been permanent healing. It didn't matter if Kabuto had neutralized it now. Without medicine, poison, whatever the man was using to suppress his immune system, the disease would come back. He would have to get the damage healed all over again.

"Were you able to make medicine?"