In addition, the HNSCC medium requires the additional addition of 50% L-WRN conditioned medium (containing Wnt Family Member 3a [Wnt3a], R-Spondin 3 [RSPO3], and Noggin proteins), 10% R-Spondin 1 [RSPO1] conditioned medium, and 100 μg/mL Primocin (for contamination prevention). Here, RSPO3 is linked to head and neck squamous cell carcinoma.