Multiple tissue Northern analysis of poly (A)⁺ RNA with TIL3 and TIL4. (A) TIL3 is predominantly expressed in PBL and ovary with a lower expression in prostate and testis. (B) TIL4 is predominantly expressed in PBL. Tissues examined: SP, spleen; TH, thymus; PR, prostate; TE, testis; OV, ovary; SI, small intestine; CO, colon; PBL, peripheral blood leukocytes. A human β-actin probe was used as a control for equivalent RNA loading.