Plays a role in modulating the extent of T-cell expansion. Enhances the expansion of TCR-stimulated T-cells by increasing their survival through enhanced expression of anti-apoptotic proteins. May modulate the capacity of T-cells to home to lymph nodes through SELL. Facilitates dedicated immune recognition of keratinocytes via interaction with its receptor KLRF2 by stimulating natural killer cell mediated cytotoxicity. Homodimer; non disulfide-linked. Interacts with KLRB1. Interacts with KLRF2. Mainly expressed in skin. Also expressed in keratinocytes, spleen, thymus, small intestine, peripheral blood monocytes, bone marrow, ovary, testis and skin. High expression in CD8(+), B-lymphocytes and naive CD4(+) T-cells. Restricted mostly to proliferating lymphocytes. Not detected in myeloid leukocytes or natural killer (NK) cells. By phytohemagglutinin (PHA) in peripheral CD8(+) T cells. N-glycosylated.