day 7 is about a main character named victor who has been diagnosed with cancer. the book begins just after one of his chemotherapy treatments, when victor is headed out on a journey, experiences a low white blood cell count, and then receives a drug to boost his white blood cell count back up to a normal level.chemotherapy patients typically experience a low point in their white blood cell count after each treatment. the low point is called the nadir, and it often occurs at about day 7 after treatment. many chemotherapy patients receive a drug (either as a shot or a patch) called pegfilgrastim, which stimulates the production of white blood cells, and thus results in raising the white blood cell count. pegfilgrastim is a longer-acting version of the earlier generation drug filgrastim. a polyethylene glycol (peg) molecule is attached to the filgrastim, resulting in pegfilgrastim, which does not get filtered out of the human body as quickly and is therefore a longer-acting drug. pegfilgrastim is the generic name of the drug, which is sold under many brand names.and now let us go together with victor on his journey.