Chemokine receptor activity regulator

Provided is a chemokine receptor activity regulator, etc. containing as the effective component thereof a pyrazolopyrimidine derivative indicated by formula (I) or a pharmaceutically acceptable salt thereof {in the formula, R1 indicates -NR1aR1b (in the formula, R1a and R1b are the same or different, and indicate a hydrogen atom, an aralkyl, etc.), R2 indicates (II) [in the formula, k and m each indicate an integer between 0 and 2, n indicates an integer between 0 and 2, L indicates a single bond, etc., R5 indicates halogen, etc., R6 indicates aryl, etc., x indicates -CR8 (in the formula, R8 indicates a hydrogen atom, etc.), etc., R7 indicates a hydrogen atom, etc.,] etc., R3 indicates -SO2R13 [in the formula, R13 indicates a lower alkoxy, -NR13d(C=0)R13e (in the formula, R13d indicates a hydrogen atom, etc., R13e indicates a lower alkyl, etc.,) etc.,] and R4 indicates a hydrogen atom, etc.}.