Receptor for thymic stromal lymphopoietin (TSLP). Forms a functional complex with TSLP and IL7R which is capable of stimulating cell proliferation through activation of STAT3 and STAT5. Also activates JAK2 (By similarity). Implicated in the development of the hematopoietic system. Heterodimer of CRLF2 and IL7R. Expressed in heart, skeletal muscle, kidney and adult and fetal liver. Primarily expressed in dendrites and monocytes. Weakly expressed in T-cells. Up-regulated in activated peripheral monocytes and THP-1 cells. The WSXWS motif appears to be necessary for proper protein folding and thereby efficient intracellular transport and cell-surface receptor binding. The box 1 motif is important for association with JAKs. The gene coding for this protein is located in the pseudoautosomal region 1 (PAR1) of X and Y chromosomes. Belongs to the type I cytokine receptor family. Type 5 subfamily.