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Figure 3. In the skin epidermis, melanocytes produce the pigment melanin in organelles called melanosomes (black dots). Melanocytes extend their dendrites contact with basal keratinocytes and transfer the pigment that accumulates in the keratinocyte to color the skin and to photoprotect the skin against ionizing radiations (UVB). Although melanocytes and keratinocytes communicate by direct contact, they also communicate via EVs. Exosomes, secreted by keratinocytes, modulate pigmentation and certainly melanocyte function. Melanocytes also secrete EVs from the endosomal system and plasma membrane that are likely to be involved in keratinocyte behavior (e.g., differentiation, proliferation, and melanosome transfer).