Ab151549

The clinical tissues and collected subcutaneous tumor tissues were fixed in fresh 4% paraformaldehyde at 4°C overnight, then dehydrated, paraffin‐embedded, and sectioned. The sections were deparaffinized, rehydrated, and subjected to H&E staining and IHC staining as described.³² In H&E staining, the tissues were stained with hematoxylin and eosin (Thermo Scientific). In IHC staining, the sections were deparaffinize, rehydrated, followed by antigen retrieval and immunostaining with different antibodies against SELENBP1 (1:200 dilution, Abcam, ab90135), SP‐C (1:200 dilution, Abcam, ab90716), Ki‐67 (1:200 dilution, Abcam, ab15580), PI3K (1:100 dilution, Abcam, ab151549), p‐PI3K (Tyr607; 1:200 dilution, Invitrogen, Catalog #PA5‐104853), AKT (1:200 dilution, CST, #4691), p‐AKT (Ser473; 1:100 dilution, CST, #4060), mTOR (1:100 dilution, CST, #2983), p‐mTOR (Ser2448; 1:200 dilution, Invitrogen, Catalog #44‐1125G), Caspase‐3 (1:200 dilution, Huabio, ET1602‐39), Cleaved‐Caspase‐3 (1:200 dilution, Affinity, AF7002), Bcl‐2 (1:200 dilution, Huabio, ET1603‐11), and Bax (1:200 dilution, Affinity, AF0120). Stains without primary antibody were used as negative control. Examined and recorded under a Zeiss Imager Z2 microscope (Carl Zeiss; 400×).

Western blotting was carried out as described previously.³¹ Primary antibodies against β‐actin (1:1000 dilution, Abcam, ab8226), SELENBP1 (1:1000 dilution, Abcam, ab90135), PI3K (1:1000 dilution, Abcam, ab151549), p‐PI3K (Tyr607; 1:1000 dilution, Invitrogen, Catalog #PA5‐104853), AKT (1:1000 dilution, CST, #4691), p‐AKT (Ser473; 1:2000 dilution, CST, #4060), mTOR (1:1000 dilution, CST, #2983), p‐mTOR (Ser2448; 1:1000 dilution, Invitrogen, Catalog #44‐1125G), Caspase‐3/p17 (1:1000 dilution, Proteintech, 66,470‐2‐Ig), Bcl‐2 (1:1000 dilution, Huabio, ET1603‐11), and Bax (1:1000 dilution, Affinity, AF0120) were used.