Anti lif

De-identified normal human colorectal tissue samples were obtained from Princeton Cancer Tissue Repository with an IRB approval. Patient consents were obtained at the time of tissue collection. IHC staining was performed as previously described^{14 (link)}. Briefly, tissue sections were deparaffinized in xylene and rehydrated in ethanol and water, followed by antigen retrieval by boiling slides in antigen unmasking solution (Vector Laboratories) for 10 min. Immunostaining was performed using the following antibodies: anti-LIF (Novus, 1:500), anti-lysozyme (Abcam, 1:5000), anti-Olfm4 (Cell signaling, 1:1000), anti-β-catenin (BD, 1:500), anti-CD44 (BioLegend, 1:500), anti-Ki67 (Abcam, 1:200), anti-DCLK (Abcam, 1:200), and anti-cleaved caspase 3 (Cell signaling, 1:500) antibodies.

IF staining of organoids was performed as previously described^{19 (link)}. Anti-Ki67 (Abcam, 1:250), anti-GFP (Abcam, 1:1000) or FITC-anti-UEA-1 (Sigma, 1:1000) antibodies were used for staining. For IF staining of mouse intestine tissues, tissue sections were deparaffinized in xylene and rehydrated with ethanol. After pre-incubation with 2% BSA and 2% goat serum, tissue sections were incubated with the anti-LIF (Novus, 1:500), anti-lysozyme (Abcam, 1:5000), anti-Olfm4 (Cell signaling, 1:1000) or anti-GFP (Abcam, 1:1000) antibodies overnight at 4° C. Slides were then incubated with Alexa Fluor® 555 Goat Anti-Rabbit IgG (H + L) or Alexa Fluor® 488 Goat Anti-mouse IgG (H + L) (1:200). Nuclei were stained with 4’, 6-diamidino-2-phenylindole (DAPI; Vector labs).