XCL1 and infection: XCL1 expression is elevated in several infections and autoimmune diseases.[29] SLAMF7 has significant role in modulating the activation and differentiation of a wide variety of immune cells and thus are involved in the regulation and interconnection of both innate and adaptive immune response.[30–32] While sex differences in immune responses have been well-documented, the underlying mechanisms remain unclear.[33] One hypothesis suggests that sex chromosomes may play a role, given that several immune-related genes are encoded on the X chromosome.