PECAM1 and neoplasm: Following immunotherapy, a significant increase of apoptotic cells (TUNEL: 16.2 ± 6.9 versus 52.3 ± 17.2; p < 0.001), and TIL (CD8+: 28.4 ± 30.7 versus 395.4 ± 522.5; p = 0.001) was observed between baseline and follow-up, as well as significantly lower microvascular density (CD31+: 304.7 ± 173.7 versus 142.1 ± 59.8; p = 0.030) and reduced tumor cell proliferation (Ki-67: 56.1 ± 14.6 versus 27.2 ± 9.7; p = 0.002).