Acquiescence is the permission to use patent of inventor. These two form a case of co- inventorship. You enjoy the right of patent being a co-inventor. You gain the right to sell the invention. US patent laws permit co-inventorship. 
 
As per section 16 of the patent act, when an invention is made jointly, the persons shall apply for patent together. The word concept is the basis of invention. Acquiescence, patent, and inventor jointly contribute to invention.

We get a co-inventorship patent. Inventors may apply jointly even under some conditions:
1] They don’t work physically together at one particular time, 2] They do not make same contribution, 3] They do not contribute to every claim of patent. One claim is enough for patent right.

Joint inventions become a joint property. The co-inventor should positively share all claims of invention. The co-inventor gets the power to license rights of patent. You do not have to take permission from co-inventor to get this power.

Under section 262 of patent act, the co-inventor can sell invention in United States without the consent of other co-inventors.  Lack of acquiescence is also called ‘patent infringement’. If patent, acquiescence, and inventor are not present, patent infringement arises. If patent is valid, there is no patent infringement.

The crux of the matter is that acquiescence, patent, and inventor are the key factors to use another's patent for profit.