Populations of PDPN+ cells among CAFs affected by environmental conditions. (A) The percentage of PDPN+ cells among CAFs changed in a time-dependent manner by culturing with DMEM-containing growth factors. (B) Populations of PDPN+ cells among CAFs changed by the addition of FBS in concentration- and time-dependent manners. The control (CTRL) condition consisted of DMEM containing 10% FBS and medium changes every day. (C) Populations of PDPN+ cells in cultures of serum-free DMEM increased more rapidly than those in cultures of glucose- and serum-free DMEM.