In our study, the clinical, laboratory, and radiological variables commonly associated with PCP that showed statistical differences were as follows: dry cough, increased respiratory frequency, decreased O2 saturation (O2sat) in arterial blood gas, elevated LDH levels, lower CRP values, low CD4 cell count, higher HIV viral load, chest X-ray showing diffuse interstitial infiltrate (DII), CT scan indicating a “ground-glass” image, presence of associated cytomegalovirus disease (CMV), and higher BDG values. The gene discussed is CD4; the disease is pneumocystosis.