PDPN and neoplasm: This was confirmed by comparative qRT‐PCR analysis of patient‐derived tumor cell spheroids (directly after isolation from ascites) and attached cells outgrown from these spheroids (7 days after plating in culture), which showed a strong upregulation of CALB2 and PDPN in the attached cells from all three samples analyzed (up to 37‐fold; Fig. 3C).