The physiological mechanisms that underlie the generation and maintenance of pain are diverse. There are afferent fibers that receive sensory information and transfer the information to the central nervous system. However, when trying to classify and determine their molecular characteristics, it becomes a difficult task due to the variety of markers that they share. With current technological advances, it is possible to specifically modulate the fibers that process pain signaling through optogenetics and chemogenetics. Nonetheless, to accomplish this aim it is necessary a specific identification of each neuron subtypes involved. This review addresses the molecular markers present in the nociceptive fibers responsible for sensory signals and the use of these molecular markers as optogenetics targets to modulate nociceptive behavior.