Valproic acid Recruiting Phase 2 Trials for EBER Positive Hodgkins and Non-hodgkins Lymphona / p16 Positive Squamous Cell Carcinoma of the Anus or Anal Canal / EBER Positive NPC / p16 Positive SCCHN / Cancer That is Associated With a Chronic Viral Infection / p16 Positive Squamous Cell Carcinoma of the Penis / p16 Positive Squamous Cell Carcinoma of the Vagina or Vulva / Squamous Cell Carcinoma of the Cervix Treatment