HTR1A and glioblastoma: Cancer specificity is another aspect we wanted to explore, and our results showed that P2RY11 (Purinergic Receptor P2Y, G-Protein Coupled, 11) is only statistically significantly upregulated in rectal adenocarcinoma, while NR1I3 (Nuclear Receptor Subfamily 1, Group I, Member 3) is uniquely downregulated in cholangiocarcinoma, PPARD (Peroxisome Proliferator-Activated Receptor Delta) in colorectal adenocarcinoma, and HTR1A (5-Hydroxytryptamine Receptor 1A) in glioblastoma.