SMAD7 and renal cell carcinoma: Through selective signal elimination analysis, we identified 13 candidate genes that might be associated with lambing trait: BMPR2, ID2, SMAD7, PLCZ, PAK1, ELOC, RAD50, H2A, H2B, THBS1, RBX1, H4, and ABCC4. Functional enrichment analysis of these genes showed that the TGF-β signaling pathway, renal cell carcinoma, non-homologous terminal junction, NETs pathway, ABC transporter, and other pathways may be involved in the regulation of lambing trait in Hotan sheep, thus influencing the fertility of this population.