Linkage between free T4 (F-T4) and loci on Chr 2, 6, 1, 18, 13, and 19 in four sets of RI mice (AXBXA, green; BXD, purple; BXH, black; and CXB, red). LRS values are on the vertical axis; Mb on the horizontal axis. The broken horizontal lines indicate the mean LRS value for all four RI sets, above which there is suggestive linkage for T-T4 for all 4 RI sets (Mean 11.3 from BXD 10.33, AXBXA 10.87, CXB 11.81, BXH 12.18). GeneNetwork (GN) identifications for F-T4: AXBXA (GN10170), BXD (GN 12584), BXH (GN 10161), CXB (GN10691). Number of strains studied: AXBXA, 15; BXD, 21; CXB, 11; BXH, 10.