RBP4 and cancer: The top uniquely upregulated genes in nsSCs included: srpx, hapln3, sema3e, zcchc24, rbp4, aqp3a, card11, arrdc2, sfrp5, and ckba. Interestingly, srpx (Srpx), the most highly, uniquely upregulated gene in nsSCs, is classified in the GO category for negative regulation of cell proliferation involved in contact inhibition and has been well documented as a suppressor gene downregulated in several cancer cell lines (Yamashita et al., 1999).