SMAD5 and schizophrenia: In summary, our screening of the 5q31-32 linkage region using DNA pooling implicates three possible candidate genes: SMAD5, TGFBI and SPRY4. While none of the findings would survive correction for multiple testing, these results were found by a systematic analysis of one of the strongest schizophrenia linkage regions, making them good candidates to study in other samples, especially samples that have shown linkage to this region.