The paired immunoglobin-like type 2 receptors consist of highly related activating and inhibitory receptors that are involved in the regulation of many aspects of the immune system. The paired immunoglobulin-like receptor genes are located in a tandem head-to-tail orientation on chromosome 7. This gene encodes the activating member of the receptor pair and contains a truncated cytoplasmic tail relative to its inhibitory counterpart (PILRA), that has a long cytoplasmic tail with immunoreceptor tyrosine-based inhibitory (ITIM) motifs.