The parents of a five-year-old boy with aggressive cancer are trying to raise funds to allow him to take part in a clinical trial in the US.
Henry Bard was diagnosed with high-risk neuroblastoma just before his fourth birthday in 2019.
His parents Graham and Rachel Bard, from Nottingham, have said they hoped to raise £202,000 to allow Henry to take part in the trial in New York.
So far, the family has raised just over £70,000.
Henry has had a seven-hour operation, stem cell harvest and high-dose chemotherapy and has spent two birthdays, and Christmas, in hospital.
His parents said raising the funds would allow Henry to take part in the Bivalent Vaccine clinical trial at the Memorial Sloan Kettering Cancer Centre in New York, as soon as he finishes frontline NHS treatment.
Mr Bard, 37, said: "Henry is such a character.
"[He] has been through so much in the last 16 months, more than most of us will experience in our lifetime let alone by the age of five.
"As parents, you feel completely helpless watching them go through aggressive and intense treatment.
"We just want to do whatever we can to give Henry the best possible chance."
Mrs Bard, 37, added: "It's been really difficult. We have been very limited and restricted as to what events and activities we can do.
"Our team of supporters have done an absolutely amazing job to raise £70k over this period."
The New York cancer centre's website said the purpose of the trial was to find what dose of a substance within a vaccine, designed to treat neuroblastoma, can be given safely to children.
The aim of the vaccine was to trigger a response of the immune system against neuroblastoma by causing the patient's body to make antibodies to attack the cancer cells.
Charity Solving Kids' Cancer said neuroblastoma returns in almost 50% of children and if this happens, fewer than one in 10 will survive.