adjective. Exhibiting a lack of responsiveness.

Not responsive.

adjective. Not responsive; unreactive.

adjective. Indifferent or apathetic; emotionless.

adjective. aloof or indifferent

adjective. not susceptible to suggestion or influence

adjective. not responding to some influence or stimulus

"In fact, only a small fraction of such treatments have been approved by the Food and Drug Administration, and virtually all the diseases that can be treated with such cells are blood diseases, while diseases of virtually every other organ remain unresponsive to adult stem cells."

cool  insusceptible  refractory  unsusceptible  

nonresponsive  responsive  

aloof  apathetic  emotionless  expressionless  flaccid  

affectless  anesthetized  arctic  autistic  blunt